WO2024037567A1

WO2024037567A1 - Hydrophilic coating, preparation method, and device

Info

Publication number: WO2024037567A1
Application number: PCT/CN2023/113384
Authority: WO
Inventors: 宗坚; 陈海力
Original assignee: 江苏菲沃泰纳米科技股份有限公司
Priority date: 2022-08-16
Filing date: 2023-08-16
Publication date: 2024-02-22
Also published as: CN117625020A

Abstract

Provided are a hydrophilic coating, a preparation method and a device. The preparation method for the hydrophilic coating comprises: mixing a siloxane monomer I containing amino groups, hydroxyl groups or carboxyl groups and an ether monomer II, gasifying the mixture, feeding same into a plasma reactor, and performing plasma discharging so as to carry out plasma polymerization on the surface of a base material to form the hydrophilic coating. The hydrophilic coating prepared by using the method has excellent hydrophilically anti-fog performance, and is little affected by water molecules and thus can still keep good hydrophilic properties when having contact and reaction with water molecules.

Description

Hydrophilic coating, preparation method and device

This application claims priority to the Chinese patent application filed with the China Patent Office on August 16, 2022, with application number 202210983271.8 and the invention title "A hydrophilic coating, preparation method and device", the entire content of which is incorporated by reference. in this application.

Technical field

The invention belongs to the field of plasma chemistry, and specifically relates to a hydrophilic coating, a preparation method and a device.

Background technique

Transparent materials (such as glass, plastic) are widely used in industrial and agricultural production, daily life and military fields, such as goggles, laser protective goggles, telescopes and lenses of various camera equipment, observation windows of various machinery, sports diving Mirrors, bathroom glass, chemical or biological protective masks, vehicle windshields and rearview mirrors, explosion protection equipment, helmets, solar panels, observation windows of measuring instruments, glass covers, glass walls of greenhouses, etc. However, in the winter, glasses will make us "see through the fog" when we breathe; in the cold winter, fogging on the surface of the windshield will greatly affect our visibility and even cause accidents. The fog problem brings a lot of inconvenience to people's work and life. The research and development of anti-fog technology and anti-fog materials have attracted much attention from the scientific and business circles.

Setting an anti-fog coating on the surface of a transparent material is a common anti-fog method. There are usually two types of anti-fog coatings. One is to form a hydrophilic surface on the surface of a transparent material, and water droplets spread to form a film on the hydrophilic surface. The other is to form an anti-fog coating on the surface of a transparent material. The first is to form a hydrophobic surface on the surface of a transparent material, and water droplets roll down on the hydrophobic surface. The disadvantage of the latter is that atomization will still occur when a large amount of water vapor condenses rapidly. The former forms a uniform water film to eliminate the diffuse reflection of light and achieve the purpose of anti-fog.

At present, the technical improvement of hydrophilic anti-fog coatings mainly focuses on traditional liquid phase processing methods, including gel-sol method, layer-by-layer self-assembly method, free radical solution polymerization method, etc. These methods generally use spraying or spin coating to apply the glue to the surface of the substrate, and then cure it using heating or UV irradiation. In the liquid phase treatment method, there is a disadvantage: the presence of solvents and reaction media may interact with the substrate. Reaction will occur, destroying the substrate structure and causing potential harm.

Plasma enhanced chemical vapor deposition (PECVD) is a chemical vapor deposition process that uses plasma generated by glow discharge to activate monomers under low pressure to produce highly active monomer free radicals or ion fragments, which are deposited on the surface of the substrate for reaction. Film formation has the advantages of fast deposition rate; good film quality, fewer pinholes, and not easy to crack; and no liquid solvent is required during the reaction process, which will not cause damage to the substrate. Therefore, PECVD technology is used to form a hydrophilic film. The preparation of anti-fog coatings provides a better choice. Hydrophilic monomers can be used to prepare good hydrophilic anti-fog coatings through PECVD. However, hydrophilic coatings prepared from common hydrophilic monomers may be easily Due to the combination with water molecules, contact with water molecules can easily lead to significant attenuation of the hydrophilic properties of the membrane layer.

Contents of the invention

Specific embodiments of the present invention provide a hydrophilic coating, a preparation method and a device whose hydrophilic properties are less affected by water molecules. The specific solutions are as follows:

A method for preparing a hydrophilic coating, including the following steps:

Provide a base material, place the base material in a plasma reactor; mix monomer I and monomer II and then vaporize and introduce them into the plasma reactor, plasma discharge, and plasma polymerization on the surface of the base material to form the hydrophilic coating;

Wherein, the monomer I has the structure shown in the following formula (1),

In formula (1), X is an amino group, a hydroxyl group or a carboxyl group, L ₁ is a C ₁ -C ₃₀ alkylene group or a C ₁ -C ₃₀ substituted alkylene group, and the substituent of the substituted alkylene group is a hydroxyl group, Amino or carboxyl group, the carbon-carbon bond of the C ₁ -C ₃₀ alkylene group or C ₁ -C ₃₀ substituted alkylene group may or may not have -O-, -S- or -NH-, so R ₁ , R ₂ or R ₃ are each independently a C ₁ -C ₅ alkyl group;

The monomer II has a structure represented by the following formula (2),

R ₇ ——R ₅ ——O——L ₂ ——O——R ₄ ——R ₆

(2) In formula (2), L ₂ is a C ₂ -C ₁₀ alkylene group or a C ₂ -C ₁₀ substituted alkylene group, the substituent of the substituted alkylene group is hydroxyl, R ₄ and R ₅ Each independently represents a connecting bond and a C ₁ -C ₄ alkylene group, and R ₆ and R ₇ each independently represent a methyl group or an epoxy group.

Optionally, the L ₁ is a C ₁ -C ₄ alkylene group, and the R ₁ , R ₂ or R ₃ are each independently a methyl group, an ethyl group or a propyl group.

Optionally, the monomer I is selected from compounds of the following structural formulas (1-1) to (1-12):

Optional, monomer I has the structure shown in the following formula (3),

In formula (3), R ₁ , R ₂ or R ₃ are independently methyl, ethyl or propyl, and n is 0, 1, 2, 3 or 4.

Optionally, the monomer I is selected from compounds of the following structural formulas (1-13) to (1-16):

Optionally, the monomer II is selected from compounds of the following structural formulas (2-1) to (2-20):

Optionally, the monomer II is selected from compounds of the following structural formulas (2-21) to (2-30):

Optionally, the molar ratio of monomer I to monomer II is 3:1-1:3.

Optionally, monomer I and monomer II are mixed, vaporized, and introduced into the plasma reactor while introducing oxygen.

Optionally, the flow rate of the mixed gas of monomer I and monomer II is 20-200 μL/min, and the flow rate of oxygen is 20-200 sccm.

Optionally, the plasma is pulse plasma, which is generated by applying pulse voltage discharge, wherein the discharge power is 10W~300W, the pulse frequency is 20Hz-10kHz, and the pulse duty cycle is 40%~80 %, plasma discharge time is 100s~36000s.

Optionally, the substrate is metal, ceramic, plastic, glass, electronic equipment or optical instruments.

A hydrophilic coating prepared by any of the above hydrophilic coating preparation methods.

A device having at least part of its surface a hydrophilic coating as described above.

The preparation method of the hydrophilic coating according to the specific embodiment of the present invention uses a siloxane monomer I containing an amino group, a hydroxyl group or a carboxyl group and a structure represented by the formula (1) and an ether monomer II having a structure represented by the formula (2). After mixing, the gasification is introduced into the plasma reactor, and the plasma is discharged. The hydrophilic coating is formed by plasma polymerization on the surface of the substrate. The hydrophilic coating prepared by this method has excellent hydrophilic anti-fogging properties and is subject to The effect of water molecules is small, and it can still maintain excellent hydrophilic properties after contact and reaction with water molecules.

Detailed ways

A specific embodiment of the present invention provides a preparation method for a hydrophilic coating, which includes the following steps:

Wherein, the monomer I has the structure shown in the following formula (1),

In formula (1), X is an amino group, a hydroxyl group or a carboxyl group, L ₁ is a C ₁ -C ₃₀ alkylene group or a C ₁ -C ₃₀ substituted alkylene group, and the substituted alkylene group refers to the alkylene group. The base has a substituent, and the substituent is a hydroxyl group, an amino group or a carboxyl group, and the carbon-carbon bond between the C ₁ -C ₃₀ alkylene group or the C ₁ -C ₃₀ substituted alkylene group may or may not With -O-, -S- or -NH-, the R ₁ , R ₂ or R ₃ are each independently a C ₁ -C ₅ alkyl group;

The monomer II has a structure represented by the following formula (2),

R ₇ ——R ₅ ——O——L ₂ ——O——R ₄ ——R ₆

(2) In formula (2), L ₂ is a C ₂ -C ₁₀ alkylene group or a C ₂ -C ₁₀ substituted alkylene group. The substituted alkylene group means that the alkylene group has a substituted group, the substituent is a hydroxyl group, R ₄ and R ₅ are each independently a connecting bond, a C ₁ -C ₄ alkylene group, R ₆ and R ₇ are each independently a methyl group or an epoxy group, considering that The hydrophilic coating can maintain better hydrophilic properties after contact reaction with water molecules. In some specific embodiments, R ₆ and R ₇ are epoxy groups.

Specific embodiments of the present invention are methods for preparing hydrophilic coatings. In some specific embodiments, the L ₁ is a C ₁ -C ₄ alkylene group. Specifically, it can be methylene, ethylene, or ethylene. propyl or butylene, and R ₁ , R ₂ or R ₃ are independently methyl, ethyl or propyl.

Specific embodiments of the present invention are methods for preparing a hydrophilic coating. In some specific embodiments, the alkylene group is a straight-chain alkylene group. In some specific embodiments, the alkylene group is an alkylene group with Branched alkylene groups include, for example, alkylene groups having branched chains such as methyl and ethyl groups.

Specific embodiments of the present invention: Preparation method of hydrophilic coating, L ₁ is a C ₁ -C ₃₀ alkylene group or a C ₁ -C ₃₀ substituted alkylene group, and the C ₁ -C ₃₀ alkylene group or The carbon-carbon bond of the C ₁ -C ₃₀ substituted alkylene group may or may not have -O-, -S- or -NH-, which means that in some specific embodiments, L ₁ is C ₁ -C ₃₀ Alkylene or C ₁ -C ₃₀ substituted alkylene. In some embodiments, at least part of the carbon-carbon bonds have -O-, -S- or -NH- C ₁ -C ₃₀ Alkylene or C ₁ -C ₃₀ substituted alkylene.

Specific embodiments of the present invention are methods for preparing hydrophilic coatings. In some specific embodiments, the monomer I is selected from compounds of the following structural formulas (1-1) to (1-12):

Specific embodiments of the present invention are methods for preparing hydrophilic coatings. In some specific embodiments, monomer I has the structure shown in the following formula (3),

In formula (3), the R1, R2 or R3 are independently methyl, ethyl or propyl, n is 0, 1, 2, 3 or 4. Specifically, for example, the monomer I can be selected from: Compounds of the following structural formulas (1-13) to (1-16):

Specific embodiments of the present invention are methods for preparing hydrophilic coatings. In some specific embodiments, the monomer II is selected from compounds of the following structural formulas (2-1) to (2-20):

In some embodiments, the monomer II is selected from compounds of the following structural formulas (2-21) to (2-30):

Specific embodiments of the present invention are methods for preparing hydrophilic coatings. In some specific embodiments, the molar ratio of monomer I and monomer II is 3:1-1:3.

Specific embodiments of the present invention are methods for preparing hydrophilic coatings. In some specific embodiments, monomer I and monomer II are mixed, vaporized, and introduced into a plasma reactor. At the same time, helium, argon, nitrogen, One or more of oxygen and hydrogen, considering better hydrophilicity, in some specific embodiments, monomer I and monomer II are mixed and then vaporized and introduced into the plasma reactor, and oxygen is introduced at the same time, In some specific embodiments, the flow rate of the mixed gas of monomer I and monomer II is 20-200 μL/min. Specific examples include 20 μL/min, 30 μL/min, 40 μL/min, 50 μL/min, 60 μL/min, 70μL/min, 80μL/min, 80μL/min, 90μL/min, 100μL/min, 110μL/min, 120μL/min, 130μL/min, 140μL/min, 150μL/min, 160μL/min, 170μL/min, 180μL/ min、 190μL/min or 200μL/min, etc., the flow rate of oxygen is 20~200sccm, specific examples can be 20sccm, 30sccm, 40sccm, 50sccm, 60sccm, 70sccm, 80sccm, 90sccm, 100sccm, 110sccm, 120sccm, 130sccm, 140sccm, 150s ccm , 160sccm, 170sccm, 180sccm, 190sccm or 200sccm, etc.

Specific embodiments of the present invention are methods for preparing hydrophilic coatings. In some specific implementations, the substrate is metal, ceramic, plastic, glass, electronic equipment or optical instruments, etc. In some specific implementations, it is considered that Super hydrophilic, the material of the substrate is glass. In some specific embodiments, the base material is a transparent material. Specifically, it can be lenses of glasses, goggles, laser protective goggles, lenses of telescopes and various camera equipment, various mechanical observation windows, and sports diving goggles. , bathroom glass, chemical or biological protective masks, vehicle windshields and rearview mirrors, explosion protection equipment, helmets, solar panels, observation windows of measuring instruments, glass covers, glass walls of greenhouses, etc.

Specific embodiments of the present invention are methods for preparing hydrophilic coatings. In order to further enhance the bonding force between the plasma coating and the substrate, in some embodiments, the substrate is pretreated with plasma before coating. , The specific pretreatment method is, for example, in an inert gas, oxygen or hydrogen atmosphere, using a plasma discharge power of 20 to 500W, a continuous discharge mode, and a continuous discharge time of 1 to 60 minutes. Considering better hydrophilicity, in some embodiments, plasma discharge is used for pretreatment in an oxygen atmosphere.

Specific embodiments of the present invention are methods for preparing hydrophilic coatings. In some specific embodiments, the thickness of the coating is 1-1000nm, specifically, 1nm, 5nm, 10nm, 20nm, 30nm, 40nm, 50nm, 100nm. , 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, etc. In some embodiments, as an ultra-thin transparent nanocoating, the coating has a thickness of 1-100 nm.

Specific embodiments of the present invention are methods for preparing hydrophilic coatings. In some specific embodiments, during the reaction process, the temperature in the plasma reactor cavity is controlled at 20°C-80°C. For example, it can be 20°C, 30°C, 40℃, 50℃, 60℃, 70℃ or 80℃, etc.; the pressure in the cavity is below 1000 millitorr, further below 500 millitorr, further below 100 millitorr; monomer I and monomer II are mixed The post-gasification temperature is 50℃-180℃. Specifically, it can be 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃ , 170℃, 180℃, etc., and vaporization occurs under vacuum conditions. The plasma is pulsed plasma, and in some In a specific embodiment, the pulsed plasma is generated by applying pulse voltage discharge, wherein the pulse discharge power is 10W to 300W. Specifically, it can be 10W, 20W, 30W, 40W, 50W, 70W, 80W, 100W, 120W, 140W. , 160W, 180W, 190W, 200W, 210W, 220W, 230W, 240W, 250W, 260W, 270W, 280W, 290W or 300W, etc., in some specific embodiments, considering better hydrophilicity, the pulse The discharge power is 60W~100W; the pulse frequency is 20Hz-10kHz. Specific examples can be 20Hz, 30Hz, 40Hz, 50Hz, 60Hz, 70Hz, 80Hz, 90Hz, 100Hz, 200Hz, 300Hz, 400Hz, 500Hz, 600Hz, 700Hz, 800Hz , 900Hz, 1KHz, 5KHz or 10KHz, etc.; the pulse duty cycle is 0.1% to 85%, specifically, it can be 0.1%, 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80% or 85%, etc., in some specific embodiments, the pulse duty cycle is 40% to 80%, further the pulse duty cycle is 45% to 75%; the plasma discharge time is 100s-36000s, specific examples can be 100s, 500s, 1000s, 1800s, 2000s, 1000s, 2000s, 3000s, 4000s, 5000s, 6000s, 7000s, 7200s, 10800s, 14400s, 18000s, 21600s, 25200s, 28800s, 32400s or 36000s and so on.

Specific embodiments of the present invention are methods for preparing hydrophilic coatings. In some specific embodiments, the plasma discharge method can be various existing discharge methods, specifically, for example, electrodeless discharge (such as radio frequency inductive coupling discharge, microwave discharge ), single-electrode discharge (such as corona discharge, plasma jet formed by unipolar discharge), double-electrode discharge (such as dielectric barrier discharge, exposed electrode radio frequency glow discharge) and multi-electrode discharge (such as using floating electrode as the third discharge of one electrode).

Specific embodiments of the present invention also provide a hydrophilic coating, which is prepared by the above preparation method of the hydrophilic coating.

The hydrophilic coating in specific embodiments of the present invention has excellent hydrophilicity and hydrophilic performance retention rate after soaking in water. In some specific embodiments, before soaking in water, the hydrophilic coating is in accordance with GB/T 30447- The water contact angle measured in 2013 was below 20°, further below 15°, further below 10°. In some embodiments, after the hydrophilic coating was soaked in water for 10 minutes, according to GB/T 30447-2013 The measured water contact angle is below 30°, and further below 20°. Compared with before immersion, the change rate of the water contact angle does not exceed 400%, further does not exceed 300%, further does not exceed 200%, and further does not exceed 150%.

Specific embodiments of the present invention also provide a device, at least part of the surface of the device has the above-mentioned hydrophilic coating. In some specific embodiments, part or all of the surface of the device is deposited with the above-mentioned hydrophilic coating. water coating.

The present invention will be further described below through specific examples.

Example

Test method description

Coating thickness test: Use the American Filmetrics F20-UV-film thickness measuring instrument for testing.

Coating water contact angle: tested according to GB/T 30447-2013 standard.

Coating transmittance and color difference: Calculated according to GB11186.3-1989 standard, and tested using a spectrophotometer. In the test results, ΔE represents color difference. T represents the light transmittance; L, a, and b represent the three color channels in the Lab color model, L represents the brightness, a represents red and green, and b represents yellow and blue.

Water immersion test: Use a 500ML beaker, fill it with half a cup of water at room temperature, and completely immerse the transparent glass piece coated with super hydrophilic nano-coating on the surface. Take it out after 10 minutes, and wait until the water stains on the surface of the sample are completely drained. Conduct coating water contact angle test.

Example 1

Place the substrate transparent glass plate (length: 75mm, width: 26mm, thickness 1mm) in the 500L plasma vacuum reaction chamber, and continuously evacuate the reaction chamber to achieve a vacuum degree of 80 mTorr, and the internal temperature of the chamber is 50°C , introduce oxygen, the flow rate is 160sccm;

Keep the chamber pressure at 80 mTorr, the oxygen flow at 160 sccm, and turn on the radio frequency plasma discharge. The radio frequency energy output mode is continuous discharge, the discharge time is 600s, and the discharge power is 300w;

Then, monomer I and monomer II with the structure shown in Table 1 below were mixed at a molar ratio of 2.6:1 and introduced into the reaction chamber. The monomer vaporization temperature was 110°C and the chamber pressure was maintained at 80 mTorr. , turn on the radio frequency plasma discharge, the radio frequency energy output mode is pulse, the discharge power, monomer flow rate and oxygen flow rate are shown in Table 1 below, the pulse frequency is 50Hz, the discharge time is 1800s, the pulse duty cycle is 45%, on the transparent glass plate Form a hydrophilic coating;

After the coating preparation is completed, air is introduced to return the reaction chamber to normal pressure, the chamber is opened, and the transparent glass plate is taken out to test the coating thickness and water contact angle. The test results are listed in Table 1.

Table 1 Monomer, plasma coating conditions and related test results of Example 1

Example 2

Then, monomer I and monomer II with the structure shown in Table 2 below were mixed at a molar ratio of 2.6:1 and introduced into the reaction chamber. The monomer vaporization temperature was 110°C and the chamber pressure was maintained at 80 mTorr. , turn on the radio frequency plasma discharge, the radio frequency energy output mode is pulse, the discharge power, monomer flow rate and oxygen flow rate are shown in Table 2 below, the pulse frequency is 50Hz, the discharge time is 1800s, the pulse duty cycle is 45%, on the transparent glass plate Form a hydrophilic coating;

After the coating preparation is completed, air is introduced to return the reaction chamber to normal pressure, the chamber is opened, and the transparent glass plate is taken out to test the coating thickness and water contact angle. The test results are listed in Table 2.

Table 2 Monomer, plasma coating conditions and related test results of Example 2

Example 3

Place the base transparent plastic PC board (length: 120mm, width: 50mm, thickness 3mm) in the 500L plasma vacuum reaction chamber, and continuously evacuate the reaction chamber to achieve a vacuum degree of 80 mTorr, and the internal temperature of the chamber is 50 ℃, introduce oxygen, the flow rate is 160sccm;

Then, monomer I and monomer II with the structure shown in Table 3 below were mixed at a molar ratio of 2.6:1 and introduced into the reaction chamber. The monomer vaporization temperature was 110°C and the chamber pressure was maintained at 80 mTorr. , turn on the radio frequency plasma discharge. The energy output mode of radio frequency is pulse. The discharge power, monomer flow rate and oxygen flow rate are shown in Table 3 below. The pulse frequency is 50Hz, the discharge time is 1800s, and the pulse duty cycle is 45%. On the transparent glass plate Form a hydrophilic coating;

After the coating preparation is completed, air is introduced to return the reaction chamber to normal pressure, the chamber is opened, and the transparent plastic PC board is taken out to test the coating thickness and water contact angle. The test results are listed in Table 3.

Table 3 Monomer, plasma coating conditions and related test results of Example 3

It can be seen from the results of Example 1 and Example 3 that the plasma coating formed by monomer I and monomer II on the transparent glass plate is super hydrophilic compared to the transparent plastic PC plate. Compared with the plastic PC plate, it shows that As a super hydrophilic coating, the plasma coating of monomer I and monomer II is more suitable for glass substrates.

Comparative Examples 1 to 2

Then, the monomer with the structure shown in Table 4 below is introduced into the reaction chamber. The monomer gasification temperature is 110°C, the chamber pressure is maintained at 80 mTorr, and the radio frequency plasma discharge is turned on. The radio frequency energy output mode is: Pulse, discharge power, monomer flow rate and oxygen flow rate are shown in Table 4 below. The pulse frequency is 50Hz, the discharge time is 1800s, the pulse duty cycle is 45%, and a hydrophilic coating is formed on the transparent glass plate;

After the coating preparation is completed, air is introduced to return the reaction chamber to normal pressure, the chamber is opened, and the transparent glass plate is taken out to test the coating thickness and water contact angle. The test results are listed in Table 4.

Table 4 Monomer, plasma coating conditions and related test results of Comparative Examples 1-2

Comparative example 3

Then, monomer I and monomer II with the structures shown in Table 5 below were introduced into the reaction chamber by mixed spraying at a flow rate of 80 μL/min and 20 μL/min respectively. The monomer vaporization temperature was 110°C and maintained The cavity pressure is 80 mTorr, turn on the radio frequency plasma discharge, the radio frequency energy output mode is pulse, the discharge power and oxygen flow are shown in Table 5 below, the pulse frequency is 50Hz, the discharge time is 1800s, and the pulse duty cycle is 45%. Transparent glass panels form a hydrophilic coating;

After the coating preparation is completed, air is introduced to return the reaction chamber to normal pressure, the chamber is opened, and the transparent glass plate is taken out to test the coating thickness and water contact angle. The test results are listed in Table 5.

Table 5 Monomer, plasma coating conditions and related test results of Comparative Example 3

Select uncoated glass sheets, 1-1, 1-3, 1-5, 1-7, 1-8, 1-9 in Example 1, Example 2, and Comparative Examples 1-3 for foaming. Water test, coating color difference and transmittance test before soaking in water, the results are listed in Table 6 below.

Table 6 Water soak test, color difference and transmittance test results

It can be seen from the results in Table 6 above that compared to the monomers of Comparative Examples 1 and 2, Example 1 The plasma coating prepared by the combination of monomer I and monomer II of 2 and 2 has a smaller water droplet angle change rate after soaking in water, indicating that the plasma coating prepared by the combination of monomers is less affected by water molecules and reacts with water molecules. It can still maintain excellent hydrophilic properties; compared with the monomer I and monomer II in Comparative Example 3, which enter the reaction chamber through different inlets for plasma coating, the monomer I and monomer in Example 1 Ⅱ is fully and uniformly mixed in advance and then enters the reaction chamber for plasma coating. It may be that the reaction between monomer Ⅰ and monomer Ⅱ is more complete, the cross-linking reaction that occurs during coating is more complete, and the consistency is better, making the coating It has stronger adhesion ability and hydrophilicity after soaking in water, which improves the lasting performance of the hydrophilic film layer. According to the results of Example 1 and Example 2, it can be seen that when monomer II includes an epoxy end group, it may have better reactivity with monomer I when mixed, so that the coating has relatively better resistance after soaking in water. Hydrophilic.

Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

A method for preparing a hydrophilic coating, characterized by comprising the following steps:

Provide a base material, place the base material in a plasma reactor; mix monomer I and monomer II and then vaporize and introduce them into the plasma reactor, plasma discharge, and plasma polymerization on the surface of the base material to form the hydrophilic coating;

Wherein, the monomer I has the structure shown in the following formula (1),

In formula (1), X is an amino group, a hydroxyl group or a carboxyl group, L 1 is a C 1 -C 30 alkylene group or a C 1 -C 30 substituted alkylene group, and the substituent of the substituted alkylene group is a hydroxyl group, Amino or carboxyl group, the carbon-carbon bond of the C 1 -C 30 alkylene group or C 1 -C 30 substituted alkylene group may or may not have -O-, -S- or -NH-, so R 1 , R 2 or R 3 are each independently a C 1 -C 5 alkyl group;

The monomer II has a structure represented by the following formula (2),
R 7 -R 5 -OL 2 -OR 4 -R 6
(2)

In formula (2), L 2 is a C 2 -C 10 alkylene group or a C 2 -C 10 substituted alkylene group. The substituent of the substituted alkylene group is hydroxyl. R 4 and R 5 are respectively independent. is a connecting bond, a C 1 -C 4 alkylene group, and R 6 and R 7 are each independently a methyl group or an epoxy group.
The method for preparing a hydrophilic coating according to claim 1, wherein the L 1 is a C 1 -C 4 alkylene group, and the R 1 , R 2 or R 3 are each independently a methyl group. , ethyl or propyl.
The method for preparing a hydrophilic coating according to claim 2, wherein the monomer I is selected from compounds of the following structural formulas (1-1) to (1-12):
The method for preparing a hydrophilic coating according to claim 1, wherein monomer I has a structure represented by the following formula (3),

In formula (3), the R 1 , R 2 or R 3 are independently methyl, ethyl or propyl, and n is 0, 1, 2, 3 or 4.
The method for preparing a hydrophilic coating according to claim 4, wherein the monomer I is selected from compounds of the following structural formulas (1-13) to (1-16):
The method for preparing a hydrophilic coating according to claim 1, wherein the monomer II is selected from compounds of the following structural formulas (2-1) to (2-20):
The method for preparing a hydrophilic coating according to claim 1, wherein the monomer II is selected from compounds of the following structural formulas (2-21) to (2-30):
The method for preparing a hydrophilic coating according to claim 1, characterized in that the molar ratio of monomer I and monomer II is 3:1-1:3.
The method for preparing a hydrophilic coating according to claim 1, characterized in that monomer I and monomer II are mixed and then vaporized and introduced into a plasma reactor while oxygen is introduced.
The method for preparing a hydrophilic coating according to claim 9, characterized in that the flow rate of the mixed gas of monomer I and monomer II is 20-200 μL/min, and the flow rate of oxygen is 20-200 sccm.
The method for preparing a hydrophilic coating according to claim 1, wherein the plasma is pulse plasma, and the pulse plasma is generated by applying pulse voltage discharge, wherein the discharge power is 10W to 300W, and the pulse plasma is Frequency is 20Hz-10kHz, pulse duty cycle is 40%~ 80%, plasma discharge time is 100s~36000s.
The method for preparing a hydrophilic coating according to claim 1, wherein the substrate is metal, ceramics, plastic, glass, electronic equipment or optical instruments.
A hydrophilic coating, characterized in that the hydrophilic coating is prepared by the preparation method of the hydrophilic coating according to any one of claims 1-12.
A device, characterized in that at least part of the surface of the device has the hydrophilic coating according to claim 13.