WO2018214448A1 - Method for preparing multifunctional protective nano coating by means of large-duty-ratio pulse discharge - Google Patents

Abstract

Disclosed is a method for preparing a multifunctional protective nano coating by means of large-duty-ratio pulse discharge, comprising the steps of: (1) putting a substrate in a reaction cavity of a nano coating preparation device, continuously vacuumizing the reaction cavity such that the degree of vacuum in the reaction cavity reaches 10 to 200 millitorrs, introducing the inert gas He or Ar into the reaction cavity, and starting a movement mechanism to make the substrate move in the reaction cavity; (2) introducing monomer vapor into the reaction cavity to reach a degree of vacuum of 30 to 300 millitorrs, and starting plasma discharge for chemical vapor deposition, wherein the deposition process comprises a preprocessing stage and a film-plating stage, in the preprocessing stage, the plasma discharge power is 120 to 400 W, and the discharge duration is 60 to 900 s, then, the film-plating stage is entered, the plasma discharge power is regulated to 50 to 200 W, and the discharge duration is regulated to 600 to 7200 s, the pulse frequency is 1 to 1000 Hz, the pulse duty ratio is 1:1 to 1:500, and a multi-functional nano coating is prepared on a surface of the substrate by means of chemical vapor deposition, the component of the monomer vapor is a mixture of at least one monofunctional unsaturated fluorocarbon resin and at least one polyfunctional unsaturated hydrocarbon derivative, and the mass fraction of the polyfunctional unsaturated hydrocarbon derivative in the monomer vapor is 15 to 65%; and (3) stopping the introduction of the monomer vapor while stopping the discharging of plasma, continuing to carry out vacuumization, keeping the reaction cavity at a degree of vacuum of 10 to 200 millitorrs for 1 to 5 min, then introducing the atmosphere to reach atmospheric pressure, stopping the movement of the substrate, and then taking out the substrate.

Description

Method for preparing multifunctional nano protective coating by large duty cycle pulse discharge Technical field

The invention belongs to the technical field of plasma chemical vapor deposition, and in particular relates to a method for preparing a multifunctional nano protective coating.

Background technique

Corrosive environments are the most common factor in the destruction of electronic devices. Corrosion of solid materials in electronic devices due to environmental corrosion, reduced conductor/semiconductor insulation, and short-circuit, open circuit, or poor contact. At present, in the products of high-tech industries such as national defense and aerospace, the proportion of electronic components is increasing, and the requirements for moisture, mildew and corrosion resistance of electronic products are becoming more and more strict. In the field of communication, with the continuous advancement of technology, the communication frequency is constantly increasing, and the requirements for the heat dissipation of communication equipment and the stability and reliability of signal transmission are also increasing. Therefore, a reliable method is needed to effectively protect the circuit board and electronic components without affecting normal heat dissipation and signal transmission.

Polymer coatings are often used for material surface protection due to their economical, easy-to-coat and wide application range, which can give materials good physical and chemical durability. Based on the barrier properties of polymer coatings, the protective film formed on the surface of electronic appliances and circuit boards can effectively isolate the circuit board, and protect the circuit from corrosion and damage in a corrosive environment, thereby improving the reliability of the electronic device. Increased safety factor and guaranteed service life are used as anti-corrosion coatings.

Conformal coating is a process of applying a specific material to a PCB to form an insulating protective layer conforming to the shape of the object to be coated. It is a commonly used circuit board waterproofing method, which can effectively isolate the circuit board. And protect the circuit from the erosion and damage of harsh environments. At present, there are some problems and drawbacks in the preparation process of the conformal coating: the solvent in the liquid phase method is easy to damage the circuit board device. Injury; heat-cured coatings tend to cause damage to the device at high temperatures; photocurable coatings are difficult to seal inside the device. Union Carbide Co. developed and applied a new conformal coating material. Parylene coating is a para-xylene polymer with low water, gas permeability and high barrier effect to achieve moisture, water and defense. Rust, acid and alkali corrosion resistance. It has been found that parylene is deposited under vacuum and can be applied to fields that cannot be covered by liquid coatings such as high frequency circuits and extremely weak current systems. The thickness of the polymer film coating is the main reason for the protection failure of the para-xylene vapor-deposited conformal coating. The polymer film coating of the printed circuit board component is prone to local rust failure at a thickness of 3 to 7 microns without affecting the high. The coating thickness should be ≥ 30 μm in the case of frequency dielectric loss. Parylene coating requires high pretreatment of printed circuit boards that need protection, such as conductive components, signal transmission components, RF components, etc., in the vapor deposition of conformal coatings, it is necessary to pre-mask the circuit board components to avoid Affects component performance. This drawback has brought great limitations to the application of parylene coating. Pyrene coatings have high cost of raw materials, harsh coating preparation conditions (high temperature, high vacuum requirements), low film formation rate, and are difficult to be widely used. In addition, thick coatings are prone to problems such as poor heat dissipation, signal blocking, and increased coating defects.

Plasma chemical vapor deposition (PCVD) is a technique in which a reactive gas is activated by a plasma to promote a chemical reaction on a surface of a substrate or a near surface to form a solid film. Plasma chemical vapor deposition coating has the following advantages

(1) It is a dry process that produces a uniform film without pinholes.

(2) The plasma polymerization film is stable in chemical and physical properties such as solvent resistance, chemical corrosion resistance, heat resistance, and abrasion resistance.

(3) The plasma polymerization film has good adhesion to the substrate.

(4) A uniform film can also be formed on the surface of the substrate having irregular irregularities.

(5) The coating preparation temperature is low, and can be carried out under normal temperature conditions, thereby effectively avoiding damage to temperature sensitive devices.

(6) The plasma process can not only prepare a coating having a thickness of a micron order but also can prepare an ultra-thin nano-scale coating.

British P2i company developed a polymer nano-coating based on a specific small duty cycle pulse discharge method using chemical vapor deposition technology, the duty cycle is less than 1:1000, based on a specific small duty cycle pulse discharge The preparation process of the method cannot achieve effective coordination and control of the bond length, bond energy, molecular weight of the material and energy supply of different groups in the chemical raw material, and the scratch resistance and durability of the prepared coating are not satisfactory. It is precisely because of the performance limitation of the coating that the coating can only form a liquid-repellent nano-coating on electronic and electrical equipment, and the corrosion resistance to the environment cannot be effectively solved. Moreover, the dense protective coating prepared based on the specific small duty cycle pulse discharge method has a fatal disadvantage: from a microscopic point of view, the smaller power density during the coating process is not conducive to the formation of a dense structure, or even a stable film. Structure; macroscopically, a smaller power density is not conducive to a large rate of growth of the coating, and its effectiveness in actual production is low, which limits its application.

In the preparation process of the existing plasma chemical vapor deposition coating, the substrate is fixed, and the motion state of the substrate is not related to the discharge energy of the plasma; the stationary substrate is treated by the continuous discharge method. The activated chain scission in the monomer is generally formed into a film by simple stacking under the action of continuous discharge, and the obtained plating layer generally has a loose structure and even a high degree of pulverization, which is disadvantageous to the formation of a microscopic dense structure of the coating layer. Waterproof, moisture-proof, corrosion-resistant, solvent-resistant and other protective properties are poor.

Due to the different regional differences in plasma density and chemical material density in the reaction chamber, the stationary state of the substrate may result in slow deposition of coatings in some regions, low production efficiency, and a large difference in uniformity and compactness.

Summary of the invention

The present invention provides a method for preparing a multifunctional nano-protective coating with a large duty cycle pulse discharge in order to solve the above technical problems. In the preparation process, the process mainly includes pretreatment and coating stages, and the pretreatment stage The segment plasma discharge mode is a high-power continuous discharge, and the plasma discharge mode in the coating stage is a large duty cycle pulse discharge. And the combination of the motion characteristics of the substrate and the plasma discharge energy, while the plasma discharge energy is output, the substrate remains in motion. Additional monomeric components with a polyfunctional crosslinked structure are introduced by plasma energy to introduce additional crosslinking sites to form a crosslinked structure. The plasma discharge generates a plasma, and by controlling the relationship between the plasma discharge energy and the bond energy of the monomer, the effective activation of the higher energy active group in the monomer component by the low temperature plasma is obtained, and at the same time, The additional active sites introduced are cross-linked and polymerized in a plasma environment to form a dense network structure.

The technical solutions adopted by the present invention are as follows:

A method for preparing a multifunctional nano-protective coating by a large duty cycle pulse discharge, comprising: the following steps:

(1) placing the substrate in a reaction chamber of the nano-coating preparation device, continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 10 to 200 mTorr, and introducing an inert gas of He or Ar. Opening the motion mechanism to cause the substrate to move in the reaction chamber;

(2) Passing monomer vapor into the reaction chamber to a vacuum of 30-300 mTorr, opening a plasma discharge, performing chemical vapor deposition, the deposition process including a pre-treatment stage and a coating stage, and a plasma discharge power in the pre-treatment stage It is 120～400W, continuous discharge time is 60～900s, then enters the coating stage. The coating stage is large duty pulse discharge, power 50～200W, time 600s～7200s, pulse frequency is 1～1000Hz, pulse duty ratio is 1. 1:1 to 1:500, preparing a multifunctional nano-coating by chemical vapor deposition on the surface of the substrate;

The purpose of the pretreatment stage is to activate the surface of the substrate to form numerous active sites on the surface of the substrate. The bombardment pretreatment can clean impurities on the surface of the substrate, and at the same time, activate the surface of the substrate, facilitate deposition of the coating, and improve the adhesion of the coating to the substrate.

The monomer vapor component is:

a mixture of at least one monofunctional unsaturated fluorocarbon resin and at least one polyfunctional unsaturated hydrocarbon derivative, wherein the mass fraction of the polyfunctional unsaturated hydrocarbon derivative in the monomer vapor is 15 65%;

(3) Stop the flow of monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber for 10~200 mTorr for 1~5min, then open the atmosphere to an atmospheric pressure to stop the movement of the substrate, then Take out the substrate.

In the pretreatment stage, the plasma discharge form is a continuous discharge with a high power of 120-400 W. The plasma discharge in the coating stage is a large duty cycle pulse discharge, the power is 50-200 W, the time is 600 s to 7200 s, the pulse frequency is 1 to 1000 Hz, and the pulse is occupied. The ratio is 1:1 to 1:500. The plasma generated by the plasma discharge deposition process has a certain etching on the deposited film; in the coating stage, the large duty cycle pulse discharge combined with the substrate motion characteristics is beneficial to accelerate the speed of chemical deposition, compared with the existing small duty cycle pulse. The discharge technology, in a certain period of time, the film obtained by the large duty cycle pulse discharge method is thicker and denser, and the coating efficiency is higher, thereby solving the specific small duty ratio of the British P2i company mentioned in the background art ( A fatal shortcoming of a dense protective coating prepared by a method of pulse discharge with a duty cycle of less than 1:1000.

In the low-vacuum plasma discharge environment, by the effective output of energy, the chemical bonds in the active monomer are controlled to break, forming higher-activity free radicals, excited free radicals and surface activation groups of mobile phones and other products. The group initiates polymerization to form a nanometer waterproof film by chemical bonding, and forms a multifunctional nano-coating on the surface of the substrate.

In the step (1), the substrate generates motion in the reaction chamber, and the substrate moves in the form of a linear reciprocating motion or a curved motion of the substrate relative to the reaction chamber, the curved motion including circular motion, elliptical motion, planetary motion, Curved motion of spherical motion or other irregular routes.

The substrate in the step (1) is a solid material, and the solid material is an electronic product, an electrical component, an electronic assembly semi-finished product, a PCB board, a metal plate, a polytetrafluoroethylene plate or an electronic component, and the After preparing the multifunctional nano-coating on the surface of the substrate, any interface can be exposed to water environment, mold environment, acid, alkaline solvent environment, acid, alkaline salt spray environment, acidic atmospheric environment, organic solvent soaking environment, cosmetic environment , sweat environment, hot and cold cycle impact environment or use in wet heat alternating environment.

The volume of the reaction chamber in the step (1) is 50 to 1000 L, the temperature of the reaction chamber is controlled at 30 to 60 ° C, and the flow rate of the inert gas is 5 to 300 sccm.

The reaction chamber is a rotating body chamber or a cubic chamber.

The monomer steam is introduced into the reaction chamber by atomizing, volatilizing and introducing the monomer into the reaction chamber by a low pressure of 10 to 200 mTorr, and the flow rate of the monomer is 10 to 1000 μL/min;

The monofunctional unsaturated fluorocarbon resin includes:

3-(Perfluoro-5-methylhexyl)-2-hydroxypropyl methacrylate, 2-(perfluorodecyl)ethyl methacrylate, 2-(perfluorohexyl)ethyl methacrylate Ester, 2-(perfluorododecyl)ethyl acrylate, 2-perfluorooctyl acrylate, 1H, 1H, 2H, 2H-perfluorooctyl acrylate, 2-(perfluorobutyl) Ethyl acrylate, (2H-perfluoropropyl)-2-acrylate, (perfluorocyclohexyl)methacrylate, 3,3,3-trifluoro-1-propyne, 1-ethynyl-3 , 5-difluorobenzene or 4-ethynyl trifluorotoluene;

The polyfunctional unsaturated hydrocarbon derivative includes:

Ethoxylated trimethylolpropane triacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol Alcohol divinyl ether or neopentyl glycol diacrylate.

In the step (2), the plasma discharge mode is radio frequency discharge, microwave discharge, intermediate frequency discharge, high frequency discharge, and electric spark discharge, and the waveforms of the high frequency discharge and the intermediate frequency discharge are sinusoidal or bipolar pulses, and the radio frequency is A plasma is a plasma generated by discharge of a high-frequency electromagnetic field. The microwave method utilizes the energy of the microwave to excite the plasma, and has the advantages of high energy utilization efficiency. At the same time, since the electrodeless discharge and the plasma are pure, it is an excellent method for high-quality, high-rate, large-area preparation.

During the preparation of the coating, the motion characteristics of the substrate and the plasma discharge energy are combined. During the plasma discharge during the preparation process, the substrate generates motion, improves the deposition efficiency of the coating, and improves the uniformity and compactness of the coating thickness.

The prepared coating has waterproof, moisture proof, mold proof, acid resistance, alkaline solvent, acid resistance, alkaline salt spray, acid resistance atmosphere, organic solvent immersion resistance, cosmetics resistance, sweat resistance, cold and heat cycle impact resistance (-40 ° C ~ +75 ° C), resistance to heat and humidity (humidity 75% to 95%) and other characteristics. With the above protective performance, the coating thickness is between 1 and 1000 nm, and the influence on the RF communication signal in the range of 10M to 8G is less than 5%.

The above technical solution of the present invention has the following advantages compared with the prior art:

1. In the coating stage, a large duty cycle pulse discharge is used, and a plasma capable of generating sufficient energy interrupts the incoming monomer segment to form more excited segments, and the excited state chain end passes through the monomer material. When an active site having a certain energy and activity and an active site corresponding to the surface energy of the substrate is combined in the form of a chemical bond, more and more complex elementary reactions are generated to form a denser network crosslinked structure;

2. During the pretreatment and coating stage, the substrate moves in the reaction chamber, so that the coating thickness of the substrate at different positions tends to be uniform, which solves the uneven thickness of the surface coating of the substrate due to the different monomer density in different regions of the reaction chamber. problem.

3. During the preparation process, the combination of the motion characteristics of the substrate and the plasma discharge energy, while the discharge energy is output, the substrate is moved, the deposition efficiency is improved, and the compactness of the multifunctional nano-protective coating is significantly improved. At the same time, due to the increase of deposition efficiency, the amount of chemical monomer raw materials used in monomer steam is only 10% to 15% of the amount in other prior art, thereby reducing emissions of exhaust gas, making it more environmentally friendly and improving actual production efficiency. It has great significance.

4. The introduction of the cross-linking structure of the polyfunctional group in the monomer material promotes the formation of the dense network structure of the coating on the microstructure, and improves the acid/alkali corrosion resistance of the coating to the environment while ensuring the hydrophobicity.

In general, plasma polymerization uses a monofunctional monomer to obtain a coating having a certain crosslinked structure. The crosslinked structure is formed by a plurality of active sites formed by chain scission of a monomer during plasma discharge by cross-linking. However, this crosslinked structure is relatively loose, contains more linear components, and is resistant to solution penetration and solubility. The present invention introduces additional crosslinking points by introducing other monomer components with a polyfunctional crosslinked structure to form a crosslinked structure. During plasma discharge, under the action of low temperature plasma, the active group with higher energy in the monomer component is broken to form an active point by effective control and output of energy, and the additional active point introduced is in the plasma environment. They cross-link and polymerize to form a dense network structure.

Compared with the coating structure with loose linear components, the mesh structure has better compactness and can effectively improve the corrosion-resistant environment of the film. In the plasma environment, the surface of the coated substrate is activated to obtain a plurality of active sites. The active sites are combined with the active radicals of the plasma-excited monomeric material with strong chemical bonds, and various forms of primitives are generated. The reaction makes the nano film of the base material have excellent bonding force and mechanical strength. By controlling the mixing mode of different monomers and controlling different process conditions at the same time, the effective control of the corrosion-resistant environment of the material surface is realized, and the structure with large roughness of the underlying dense surface layer with special microstructure is obtained, and the comprehensive performance of environmental corrosion resistance is obtained. Increased by 20% to 35%.

5. By introducing other monomers of cross-linking structure, controlling the monomer ratio, according to the difference of molecular bond energy, bond length and vaporization temperature of different monomers, the corresponding energy output and effective changes of process parameters are given to the device. The composite nano-coating with a composite structure and a gradual structure not only ensures the hydrophobicity of the film, but also improves the environmental corrosion resistance of products such as electronic products.

Electronic equipment in daily life is extremely vulnerable to corrosion by corrosive environments, and is basically in a corrosive environment during use. In the long run, it will cause irreparable damage to electronic equipment. The coating method of the patent of the invention greatly increases the significance of the nanometer in improving the actual production efficiency. Coating in rot The service life of the erosive environment improves the protection of the product. Mainly used in the following products:

(1), portable device keyboard: portable keyboard has small and light features, commonly used in computers, mobile phones and other equipment. It makes it easy for users to work on the journey. However, when it encounters the contamination of common liquids, such as the accidental overturn of the water cup, the soaking of rain and sweat, the inside of the keyboard is easily short-circuited and damaged. After coating with this type of nano-coating, it can ensure that the surface of the keyboard is easy to clean and function properly after being exposed to water, so that the keyboard can adapt to a more severe environment.

(2), LED display: LED display has product promotion, store decoration, lighting, warning and other purposes. Some of its uses need to face the harsh environment of rain or dust, such as the rainy days, the mall's open-air LED advertising screen, road warning lights, LED display control panel in the production workshop, these harsh environments lead to LED screen failure, and easy to accumulate dust, It is difficult to clean, and after using the nano-coating, the above problems can be effectively solved.

(3), intelligent fingerprint lock: fingerprint lock is a smart lock, which integrates computer information technology, electronic technology, mechanical technology and modern hardware technology, is widely used in public security criminal investigation and judicial field. However, after it meets water, its internal circuit is short-circuited, difficult to repair, and requires violent de-locking. This coating can be used to avoid this problem.

(4), hearing aid, Bluetooth headset: There is no communication line between the hearing aid and the Bluetooth headset. After using this coating, the user can use it in a water environment for a certain period of time, such as bathing, raining, the equipment will not be infiltrated by rain. damage.

(5) Some sensors: Some sensors need to work in a liquid environment, such as water pressure, oil pressure sensors, and sensors used in underwater operation equipment, as well as sensors that often encounter water in the working environment. These sensors use this coating. After the layer, it can guarantee that the sensor will not malfunction due to the liquid invading the internal structure of the mechanical device.

(6) Most 3C products: such as mobile phones, notebooks, PSPs, etc.

(7) Other equipment that needs to be waterproof: including equipment that needs to work in a humid environment, or may encounter unexpected accidents such as liquid spills, which may affect the normal operation of internal weak current lines.

The multifunctional nano-coating prepared by the method can also be applied to the following different environments and related products involved:

Waterproof, moisture proof, moldproof:

1 House interior: bathroom top, wallpaper, chandeliers, curtains, screens. 2 daily necessities: mosquito nets, table lamp covers, chopsticks, car rearview mirrors. 3 Cultural relics and works of art: copybooks, antiques, woodcarving, leather, bronze, silk, costumes, ancient books. 4 Electronic components and electronic products: sensors (working in wet or dusty environments), chips of various electronic products (electronic sphygmomanometers, smart watches), circuit boards, mobile phones, LED screens, hearing aids. 5 precision instruments and optical equipment: mechanical watches, microscopes.

Acid and alkaline solvents, acid and alkali salt spray, acid resistant atmosphere:

1 housing interior parts: wallpaper, tiles. 2 protective equipment: acid (alkali) gloves, acid (alkali) protective clothing. 3 Mechanical equipment and pipelines: flue desulfurization equipment, seals (acid/alkaline lubricants), pipes, valves, large-diameter sea pipelines, etc. 4 various reactors, reactors. 5 chemical production, storage; sewage treatment, aeration tank; 6 other: acid and alkali workshop, anti-alkali aerospace, energy and power, steel and metallurgy, petrochemical, medical and other industries, storage containers, statues (reduced acid rain Corrosion), sensor (acid/alkaline environment).

Soaked with organic solvents, resistant to cosmetics, sweat resistant:

1 such as paraffin, olefin, alcohol, aldehyde, amine, ester, ether, ketone, aromatic hydrocarbon, hydrogenated hydrocarbon, terpene olefin, halogenated hydrocarbon, heterocyclic compound, nitrogen-containing compound and sulfur compound solvent; 2 cosmetic packaging container ; 3 fingerprint lock, headphones.

Resistance to cold and heat cycle (-40 ° C ~ +75 ° C), resistance to heat and humidity (humidity 75% ~ 95%): electrical, electronic, automotive electrical, such as aviation, automotive, home appliances, scientific research and other fields of equipment.

detailed description

The invention is described in detail below with reference to the drawings and specific embodiments, but the invention is not limited to the specific embodiments.

Example 1

A method for preparing a multifunctional nano-protective coating by a large duty cycle pulse discharge comprises the following steps:

(1) placing the substrate in the reaction chamber of the nano-coating preparation device, closing the reaction chamber and continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 10 mTorr, and introducing an inert gas Ar, Opening the moving mechanism to cause the substrate to move in the reaction chamber; the substrate in the step (1) is a solid material, the solid material is a bulk aluminum material, and the surface of the substrate is prepared to be resistant to organic solvents and resistant to cosmetics. Any interface after coating can be exposed to an organic solvent test environment.

The volume of the reaction chamber in the step (1) was 50 L, the temperature of the reaction chamber was controlled at 30 ° C, and the flow rate of the inert gas was 5 sccm.

In the step (1), the substrate moves in the reaction chamber, and the substrate moves in the form of a circular motion of the substrate relative to the reaction chamber at a rotation speed of 3 rpm.

(2) Passing monomer vapor into the reaction chamber to a vacuum of 30 mTorr, plasma discharge is started, and chemical vapor deposition is performed. The deposition process includes a pretreatment stage and a coating stage, and the plasma discharge power of the pretreatment stage is 120 W. , 900s, then enter the coating stage, the plasma discharge in the coating stage is a large duty cycle pulse discharge, power 50W, time 7200s, pulse frequency is 1Hz, pulse duty ratio is 1:1, prepared by chemical vapor deposition on the substrate surface Multifunctional nano coating;

In step (2):

Passing monomer steam to atomize and volatilize the monomer through the feed pump, and introduce the reaction chamber into the reaction chamber by a low pressure of 10 mTorr, and the flow rate of the monomer vapor is 1000 μL/min;

The monomer vapor composition is:

a mixture of two monofunctional unsaturated fluorocarbon resins and two polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of the polyfunctional unsaturated hydrocarbon derivative in the monomer vapor is 15%;

The monofunctional unsaturated fluorocarbon resin is: 2-perfluorooctyl acrylate ethyl ester, 2-(perfluorohexyl) ethyl methacrylate;

The polyfunctional unsaturated hydrocarbon derivative is: ethylene glycol diacrylate, 1,6-hexanediol diacrylate;

The plasma discharge mode in the step (2) is continuous radio frequency discharge.

(3) At the end of the coating, stop the flow of the raw material monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber at 10 mTorr, and then open the atmosphere to an atmospheric pressure after 1 min, then take out the substrate. .

The obtained performance test results of aluminum sheets deposited with organic solvent-resistant and cosmetic-resistant coatings are as follows:

(1) Hydrophobic and oleophobic effects

(2) Organic solvent resistance test results: (pass means that the contact angle changes less than 5° after immersion for a period of time)

(3) Acid and alkaline test results: (pass indicates that corrosion does not occur after a period of time)

Example 2

A method for preparing a multifunctional nano-protective coating by a large duty cycle pulse discharge comprises the following steps:

(1) placing the substrate in the reaction chamber of the nano-coating preparation device, closing the reaction chamber and continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 60 mTorr, and introducing an inert gas He to start a moving mechanism that moves the substrate;

The substrate in the step (1) is a solid material, the solid material is a bulk aluminum alloy material, and any interface of the surface of the substrate can be exposed to an acid or alkali test environment after preparing an acid-proof and alkaline environment coating. .

The volume of the reaction chamber in the step (1) was 250 L, the temperature of the reaction chamber was controlled at 40 ° C, and the flow rate of the inert gas was 15 sccm.

In the step (1), the substrate is subjected to planetary motion, the revolution speed is 2 rpm, and the rotation speed is 3.5 rpm.

(2) Passing monomer vapor into the reaction chamber, when the vacuum degree is 90 mTorr, the plasma discharge is started, chemical vapor deposition is performed, the power in the pretreatment stage is 200 W, the time is 700 s, and then enters the coating stage, and the plasma discharge in the coating stage For the large duty cycle pulse discharge, the power is 80W, the time is 6300s, the pulse frequency is 20Hz, the pulse duty ratio is 1:60, and the multifunctional nano-coating is prepared by chemical vapor deposition on the surface of the substrate.

In step (2):

The monomer steam is introduced into the reaction chamber by the atomization pump, and is introduced into the reaction chamber by a low pressure of 60 mTorr, and the flow rate of the monomer vapor is 700 μL/min;

The monomer vapor composition is:

a mixture of three monofunctional unsaturated fluorocarbon resins and two polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of polyfunctional unsaturated hydrocarbon derivatives in the monomer vapor is 35%;

The monofunctional unsaturated fluorocarbon resin is: 2-(perfluorodecyl)ethyl methacrylate, 2-(perfluorododecyl)ethyl acrylate, (perfluorocyclohexyl)methyl Acrylate;

The polyfunctional unsaturated hydrocarbon derivative is: tripropylene glycol diacrylate and polyethylene glycol diacrylate;

In the step (2), the plasma discharge mode is an intermediate frequency continuous discharge, and the waveform of the intermediate frequency discharge is sinusoidal.

(3) At the end of the coating, stop the flow of the raw material monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber at 80 mTorr, and then open the atmosphere to an atmospheric pressure after 2 min, then take out the substrate. .

After the above aluminum alloy material is coated, the performance test results are as follows:

(1) Hydrophobic and oleophobic effects

(2) Organic solvent resistance test results: (pass means that the contact angle changes less than 5° after immersion for a period of time)

(3) Acid and alkaline test results: (pass indicates that corrosion does not occur after a period of time)

Example 3

A method for preparing a multifunctional nano-protective coating by a large duty cycle pulse discharge comprises the following steps:

(1) placing the substrate in the reaction chamber of the nano-coating preparation device, closing the reaction chamber and continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 130 mTorr, and introducing an inert gas Ar to start. a moving mechanism that moves the substrate;

The substrate in the step (1) is a solid material, the solid material is a bulk aluminum material and a PCB board, and the surface of the substrate is prepared to be exposed to cold and heat after being subjected to a cold and heat resistant cyclic impact coating. In a loop test environment.

The volume of the reaction chamber in the step (1) was 480 L, the temperature of the reaction chamber was controlled at 50 ° C, and the flow rate of the inert gas was 60 sccm.

In step (1), the substrate is subjected to a circular motion at a rotation speed of 5 rpm.

(2) Passing monomer vapor into the reaction chamber, when the vacuum degree is 150 mTorr, the plasma discharge is started, chemical vapor deposition is performed, the power of the pretreatment stage is 250 W, the time is 580 s, and then enters the coating stage, and the plasma discharge in the coating stage For the large duty cycle pulse discharge, the power is 140W, the time is 5000s, the pulse frequency is 90Hz, the pulse duty ratio is 1:110, and the multifunctional nano-coating is prepared by chemical vapor deposition on the surface of the substrate.

In step (2):

The monomer steam is introduced into the reaction chamber by atomizing and volatilizing the monomer through a feed pump, and the flow rate of the monomer vapor is 550 μL/min;

The monomer vapor composition is:

a mixture of two monofunctional unsaturated fluorocarbon resins and two polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of polyfunctional unsaturated hydrocarbon derivatives in the monomer vapor is 32%;

The monofunctional unsaturated fluorocarbon resin is: (perfluorocyclohexyl) methacrylate and 2-(perfluorohexyl) Ethyl methacrylate;

The polyfunctional unsaturated hydrocarbon derivative is: ethoxylated trimethylolpropane triacrylate and diethylene glycol divinyl ether;

In the step (2), the plasma discharge mode is a high-frequency continuous discharge, and the waveform of the high-frequency discharge is a bipolar pulse.

(3) At the end of the coating, stop the flow of the raw material monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber at 130 mTorr, and then open the atmosphere to an atmospheric pressure after 3 minutes, then take out the substrate. .

After the above-mentioned block aluminum material and PCB board coating, the results of the thermal cycle impact test:

Example 4

A method for preparing a multifunctional nano-protective coating by a large duty cycle pulse discharge comprises the following steps:

(1) placing the substrate in the reaction chamber of the nano-coating preparation device, closing the reaction chamber and continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 160 mTorr, and introducing an inert gas He to start a moving mechanism that moves the substrate;

The substrate in the step (1) is a solid material, the solid material is a bulk aluminum material, and the substrate After the surface is prepared to withstand the wet heat alternating coating, any of its interfaces can be exposed to the damp heat test environment.

The volume of the reaction chamber in the step (1) was 680 L, the temperature of the reaction chamber was controlled at 50 ° C, and the flow rate of the inert gas was 160 sccm.

In the step (1), the substrate is linearly reciprocated at a speed of 12 mm/min.

(2) Passing monomer vapor into the reaction chamber, when the vacuum degree is 190 mTorr, the plasma discharge is turned on, chemical vapor deposition is performed, the power in the pretreatment stage is 300 W, the time is 350 s, and then enters the coating stage, and the plasma discharge in the coating stage For the large duty cycle pulse discharge, the power is 230W, the time is 2500s, the pulse frequency is 380Hz, the pulse duty ratio is 1:260, and the multifunctional nano-coating is prepared by chemical vapor deposition on the surface of the substrate.

In step (2):

The monomer steam is introduced into the reaction chamber by atomizing and volatilizing the monomer, and is introduced into the reaction chamber by a low pressure of 160 mTorr, and the flow rate of the monomer vapor is 220 μL/min;

The monomer vapor composition is:

a mixture of three monofunctional unsaturated fluorocarbon resins and three polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of polyfunctional unsaturated hydrocarbon derivatives in the monomer vapor is 51%;

The monofunctional unsaturated fluorocarbon resin is: 3,3,3-trifluoro-1-propyne, 3-(perfluoro-5-methylhexyl)-2-hydroxypropyl methacrylate, 1H , 1H, 2H, 2H-perfluorooctyl acrylate;

The polyfunctional unsaturated hydrocarbon derivatives are: ethoxylated trimethylolpropane triacrylate, ethylene glycol diacrylate and 1,6-hexanediol diacrylate;

The plasma discharge mode in the step (2) is microwave continuous discharge.

(3) At the end of the coating, stop the flow of the raw material monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber at 160 mTorr, and then open the atmosphere to an atmospheric pressure after 4 minutes, then take out the substrate. .

The bulk aluminum material after the above coating, the wet heat alternating test results are as follows:

Example 5

A method for preparing a multifunctional nano-protective coating by a large duty cycle pulse discharge comprises the following steps:

(1) placing the substrate in the reaction chamber of the nano-coating preparation device, closing the reaction chamber and continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 200 mTorr, and introducing an inert gas Ar to start. a moving mechanism that moves the substrate;

The substrate in the step (1) is a solid material, the solid material is a bulk polytetrafluoroethylene plate, and any interface of the surface of the substrate can be exposed to GJB150.10A-2009 mold test after preparing an anti-fungal coating. Used in the environment.

The volume of the reaction chamber in the step (1) was 1000 L, the temperature of the reaction chamber was controlled at 60 ° C, and the flow rate of the inert gas was 300 sccm.

In the step (1), the substrate was subjected to a curve reciprocating motion at a speed of 100 mm/min.

(2) Passing monomer vapor into the reaction chamber, when the vacuum degree is 300 mTorr, the plasma discharge is turned on, chemical vapor deposition is performed, the power in the pretreatment stage is 400 W, the time is 60 s, and then enters the coating stage, and the plasma discharge in the coating stage For large duty cycle pulse discharge, power 360W, time 1200s, pulse frequency The rate is 850 Hz, the pulse duty ratio is 1:370, and a multifunctional nano-coating is prepared by chemical vapor deposition on the surface of the substrate.

In step (2):

The monomer steam is introduced into the reaction chamber by atomizing and volatilizing the monomer through a feed pump, and the flow rate of the monomer vapor is 10 μL/min;

The monomer vapor composition is:

a mixture of three monofunctional unsaturated fluorocarbon resins and two polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of the polyfunctional unsaturated hydrocarbon derivative in the monomer vapor is 65%;

The monofunctional unsaturated fluorocarbon resin is: 1H, 1H, 2H, 2H-perfluorooctyl acrylate, 3,3,3-trifluoro-1-propyne and 2-(perfluorohexyl)ethyl Methacrylate

The polyfunctional unsaturated hydrocarbon derivative is: tripropylene glycol diacrylate and ethylene glycol diacrylate;

The plasma discharge mode in the step (2) is a spark discharge.

(3) At the end of the coating, stop the flow of the raw material monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber at 200 mTorr, and then open the atmosphere to an atmospheric pressure after 5 minutes, then take out the substrate. .

The above-mentioned coated polytetrafluoroethylene sheet, GJB150.10A-2009 mold test results:

Sample Water contact angle Mildew resistance Surface mold spot degree PTFE plate 134° level 2 5% or so

Example 6

This embodiment is the same as the basic process steps of Embodiment 1, and the different process parameters are as follows:

1. Step (1) pumping the vacuum in the reaction chamber to 120 mTorr, and introducing an inert gas Ar;

Step (1) The substrate is a solid material, the solid material is an electrical component, and any interface of the surface of the substrate after being prepared with a waterproof and electrical breakdown coating can be exposed to the environment described in the international industrial waterproof rating standard IPX7. use.

The volume of the reaction chamber in the step (1) was 400 L, the temperature of the reaction chamber was controlled at 40 ° C, and the flow rate of the inert gas was 150 sccm.

(2) Passing monomer vapor into the reaction chamber, when the vacuum degree is 160 mTorr, the plasma discharge is started, chemical vapor deposition is performed, the power of the pretreatment stage is 380 W, the time is 400 s, and then enters the coating stage, and the plasma discharge in the coating stage For large duty cycle pulse discharge, power 400W, time 600s, pulse frequency is 1000Hz, pulse duty ratio is 1:500, and multi-functional nano-coating is prepared by chemical vapor deposition on the surface of the substrate.

In the step (2): the monomer steam is introduced into the monomer through the feed pump for atomization, volatilization, introduced into the reaction chamber by a low pressure of 160 mTorr, the flow rate of the monomer vapor is 200 μL / min;

The monomer vapor composition is:

a mixture of four monofunctional unsaturated fluorocarbon resins and two polyfunctional unsaturated hydrocarbon derivatives, the mass fraction of polyfunctional unsaturated hydrocarbon derivatives in the monomer vapor is 48%;

The monofunctional unsaturated fluorocarbon resin is: 2-(perfluorodecyl)ethyl methacrylate, 1H, 1H, 2H, 2H-perfluorooctyl acrylate, 3,3,3-trifluoro 1-propyne and 2-(perfluorohexyl)ethyl methacrylate;

The polyfunctional unsaturated hydrocarbon derivative is: tripropylene glycol diacrylate and diethylene glycol divinyl ether;

2. Step (3) Keep the vacuum of the reaction chamber at 160 mTorr for 5 min and then pass to the atmosphere to an atmospheric pressure.

The above-mentioned coated electrical components are resistant to underwater electricity, and the underwater immersion test results are as follows:

The following table tests the time taken for the coating prepared in this example to reach 1 mA at different voltages:

IPX 7 waterproof rating test (underwater 1m immersion test for 30min) Results: Electrical components are working properly.

Claims (8)

A method for preparing a multifunctional nano-protective coating by a large duty cycle pulse discharge, comprising: the following steps: (1) placing the substrate in a reaction chamber of the nano-coating preparation device, continuously evacuating the reaction chamber, pumping the vacuum in the reaction chamber to 10 to 200 mTorr, and introducing an inert gas of He or Ar. Opening the motion mechanism to cause the substrate to move in the reaction chamber; (2) Passing monomer vapor into the reaction chamber to a vacuum of 30-300 mTorr, opening a plasma discharge, performing chemical vapor deposition, the deposition process including a pre-treatment stage and a coating stage, and a plasma discharge power in the pre-treatment stage It is 120-400W, continuous discharge time is 60-900s, and then enters the coating stage. The plasma discharge in the coating stage is large duty pulse discharge, power 50~200W, time 600s~7200s, pulse frequency is 1~1000Hz, pulse duty a ratio of 1:1 to 1:500, preparing a multifunctional nano-coating by chemical vapor deposition on the surface of the substrate; The monomer vapor component is: a mixture of at least one monofunctional unsaturated fluorocarbon resin and at least one polyfunctional unsaturated hydrocarbon derivative, wherein the mass fraction of the polyfunctional unsaturated hydrocarbon derivative in the monomer vapor is 15 65%; (3) Stop the flow of monomer vapor, stop the plasma discharge, continue to vacuum, keep the vacuum of the reaction chamber for 10~200 mTorr for 1~5min, then open the atmosphere to an atmospheric pressure to stop the movement of the substrate, then Take out the substrate. The method for preparing a multifunctional nano-protective coating according to a large duty cycle pulse discharge according to claim 1, wherein in the step (1), the substrate generates motion in the reaction chamber, and the substrate moves The substrate is linearly reciprocated or curved relative to the reaction chamber, including curved motion, elliptical circumferential motion, planetary motion, spherical motion, or other irregularly curved motion. Multifunctional nanometer protective coating prepared by a large duty cycle pulse discharge according to claim The method of layer, characterized in that: in the step (1), the substrate is a solid material, and the solid material is an electronic product, an electrical component, an electronic assembly semi-finished product, a PCB board, a metal plate, a Teflon sheet or an electronic element. a device, and the interface of the substrate can be exposed to a water environment after the preparation of the multifunctional nano-coating, mold environment, acid, alkaline solvent environment, acid, alkaline salt spray environment, acidic atmospheric environment, organic solvent Soaking environment, cosmetic environment, sweat environment, hot and cold cycle impact environment or wet heat alternating environment. The method for preparing a multifunctional nano-protective coating according to a large duty cycle pulse discharge according to claim 1, wherein the volume of the reaction chamber in the step (1) is 50 to 1000 L, and the reaction chamber The temperature is controlled at 30 to 60 ° C, and the flow rate of the inert gas is 5 to 300 sccm. A method for preparing a multifunctional nano-protective coating by a large duty cycle pulse discharge according to claim 1 or 4, wherein the reaction chamber is a rotating body chamber or a cubic chamber. The method for preparing a multifunctional nano-protective coating according to a large duty cycle pulse discharge according to claim 1, wherein in the step (2), the monomer steam is introduced to pass the monomer through the feeding pump. It is atomized, volatilized and introduced into the reaction chamber from a low pressure of 10 to 200 mTorr, and the flow rate of the introduced monomer is 10 to 1000 μL/min. A method for preparing a multifunctional nano-protective coating by using a large duty cycle pulse discharge according to claim 1, wherein: The monofunctional unsaturated fluorocarbon resin includes: 3-(Perfluoro-5-methylhexyl)-2-hydroxypropyl methacrylate, 2-(perfluorodecyl)ethyl methacrylate, 2-(perfluorohexyl)ethyl methacrylate Ester, 2-(perfluorododecyl)ethyl acrylate, 2-perfluorooctyl acrylate, 1H, 1H, 2H, 2H-perfluorooctyl acrylate, 2-(perfluorobutyl) Ethyl acrylate, (2H-perfluoropropyl)-2-acrylate, (perfluorocyclohexyl)methacrylate, 3,3,3-trifluoro-1-propyne, 1-ethynyl-3 , 5-difluorobenzene or 4-ethynyl trifluorotoluene; The polyfunctional unsaturated hydrocarbon derivative includes: Ethoxylated trimethylolpropane triacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol Alcohol divinyl ether or neopentyl glycol diacrylate. The method for preparing a multifunctional nano-protective coating by using a large duty cycle pulse discharge according to claim 1, wherein in the step (2), the plasma discharge mode is radio frequency discharge, microwave discharge, and intermediate frequency Discharge, high frequency discharge, spark discharge, the waveform of the high frequency discharge and the intermediate frequency discharge is a sinusoidal or bipolar pulse.