A hydrophilic coating, method of manufacture and device

Abstract

The detailed description of the present application provides a hydrophilic coating, a preparation method and a device, the hydrophilic coating is that a substrate contacts a plasma of a hydrophilic monomer A with an amino group and a silane monomer B with an epoxy group, so that a coating formed by plasma polymerization on the surface of the substrate, or a composite coating formed by the substrate successively contacting the plasma of the monomer B and the plasma of the monomer A, the hydrophilic coating has excellent hydrophilic performance, light transmittance, and very excellent wear resistance.

Description

Technical Field

[0001] This invention relates to the field of plasma chemistry, and in particular to a hydrophilic coating, its preparation method, and a device. Background Technology

[0002] Transparent materials (such as glass and plastics) have wide applications in industrial and agricultural production, daily life, and the military. Examples include safety goggles, laser protective goggles, lenses for telescopes and various camera equipment, observation windows for various machines, diving masks, bathroom glass, chemical or biological protective masks, vehicle windshields and rearview mirrors, bomb disposal protective equipment, helmets, solar panels, observation windows for measuring instruments, glass covers, and glass walls for greenhouses. However, in winter, breathing on glasses can cause fogging, making it difficult to see clearly. In cold winters, fogging on windshields can significantly reduce visibility and even cause accidents. Fogging problems bring many inconveniences to people's work and lives, making the research and development of anti-fogging technologies and materials a focus of attention for the scientific and industrial communities.

[0003] Applying an anti-fogging coating to the surface of transparent materials is a common method for preventing fogging. There are generally two types of anti-fogging coatings: one forms a hydrophilic surface on the transparent material, where water droplets spread and form a film; the other forms a hydrophobic surface, where water droplets bead up and roll off. The latter has the drawback that fogging can still occur when a large amount of water vapor condenses rapidly. The former forms a uniform water film to eliminate diffuse reflection of light, thus achieving the purpose of preventing fogging.

[0004] Currently, technological improvements in hydrophilic antifog coatings mainly focus on traditional liquid-phase treatment methods, including gel-sol methods, layer-by-layer self-assembly methods, and free radical solution polymerization methods. These methods generally use spraying or spin coating to apply adhesive to the substrate surface, followed by curing using heating or UV irradiation. A drawback of liquid-phase treatment methods is that the presence of solvents and reaction media may react with the substrate, damaging its structure and causing potential hazards.

[0005] Plasma-enhanced chemical vapor deposition (PECVD) is a chemical vapor deposition process that uses plasma generated by glow discharge under low pressure to activate monomers, producing highly reactive monomer radicals or ionic fragments that are deposited onto the substrate surface to form a film. PECVD offers advantages such as fast deposition rate, high film quality, uniform film, fewer pinholes, and resistance to cracking. Since it does not require liquid solvents during the reaction and does not damage the substrate, PECVD technology provides a better option for preparing anti-fogging hydrophilic coatings. Summary of the Invention

[0006] A specific embodiment of the present invention provides a hydrophilic coating, which has excellent hydrophilic properties and light transmittance, while also exhibiting excellent wear resistance. The specific solution is as follows:

[0007] A hydrophilic coating, wherein the hydrophilic coating is a coating formed by plasma polymerization on the surface of a substrate through contact with plasma containing monomer A and monomer B, or the hydrophilic coating is a composite coating formed by sequential contact of a substrate with plasma containing monomer B and plasma containing monomer A.

[0008] Wherein, monomer A simultaneously contains an imino group, and at least one of a hydroxyl, carboxyl, or amino group;

[0009] The result of monomer B is shown in equation (1) below.

[0010]

[0011] In equation (1), R4 and R5 are independently selected from hydrogen atoms, C1-C atoms, and C5, respectively. 10 Alkyl, C1-C 10 Substituted alkyl groups, C1-C 10 alkoxy or C1-C 10 The substituted alkoxy group, R6 is C1-C 10 Alkyl, C1-C 10 Substituted alkyl groups, C1-C 10 alkoxy or C1-C 10 The substituted alkoxy group is L, which is the linking moiety, and Z is the oxocyclic alkyl group.

[0012] Optionally, the structure of monomer A is shown in equation (2) below.

[0013] R2-NH-R1-X1 (2)

[0014] In equation (2), R1 is C1-C 10 alkylene or C1-C 10 Substituted alkylene groups, where R2 is a hydrogen atom, C1-C 10 Alkyl, C1-C 10 The substituted alkyl group or the group with the structure shown in formula (3) below, where X1 is a hydroxyl, carboxyl or amino group;

[0015] X2-R3-* (3)

[0016] In equation (3), R3 is C1-C 10 alkylene or C1-C 10 The substituted alkylene group, X2 is a hydroxyl, carboxyl or amino group.

[0017] Optionally, R1 is selected from C1-C4 alkylene or C1-C4 substituted alkylene, and R3 is selected from C1-C4 alkylene or C1-C4 substituted alkylene.

[0018] Optionally, monomer A is ethanolamine, diethanolamine, N1-(2-methoxyethyl)-1,3-propanediamine, aziridine-3-ol, diisopropanolamine, sarcosine, 2-butanoethanol, hydroxyethyl ethylenediamine, N-(2-hydroxyethyl)-1,3-propanediamine, N-methyl-2-hydroxyethylamine, iminodiacetic acid, or 2-(ethylamino)prop-1-ol.

[0019] Optionally, R4 and R5 are each independently selected from C1-C4 alkoxy groups, R6 is a C1-C4 alkoxy group or a C1-C4 alkyl group, and Z is an epoxy group.

[0020] Optionally, R4 and R5 are each independently selected from methoxy or ethoxy, and R6 is methoxy, ethoxy, methyl, or ethyl.

[0021] Optionally, L is C1-C 10 alkylene or alkeneoxy groups.

[0022] Optionally, monomer B is 3-(2,3-epoxypropoxy)propyltrimethoxysilane, epoxybutyltrimethoxysilane, or 3-glycidyl etheroxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, 3-glycidyl etheroxypropyltriethoxysilane, 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane, triethoxy At least one of the following: 1-methyl-2-(ethylene oxide methoxy)ethylsilane, trimethoxy-7-oxabicyclo[4.1.0]hept-3-ylsilane, 10-ethylene oxide-2-decyltrimethoxysilane, 6,6-bis(2-methoxyethoxy)ethylene oxide-11-yl-2,5,10-trioxa-6-silane undecane, [3-(1,3-dioxolane-4-ylmethoxy)propyl]trimethoxysilane, or 3-(trimethoxysilyl)propyl glycidyl ether.

[0023] Optionally, the molar ratio of monomer A to monomer B is 1:1 to 1:5.

[0024] Optionally, the substrate may be an optical instrument, metal, ceramic, plastic, glass, or electronic device.

[0025] Optionally, the light transmittance of the hydrophilic coating is above 90%.

[0026] Optionally, the water contact angle measured by the hydrophilic coating is below 10°.

[0027] Optionally, the hydrophilic coating is rubbed 200 times with an alcohol-soaked cotton cloth at a thread length of 4 cm and a speed of 40 r / min under a 10 N load, and the measured change in water contact angle is no greater than 2°.

[0028] A method for preparing the hydrophilic coating described above includes the following steps:

[0029] A substrate is provided, which is placed in a plasma reactor. The gaseous forms of monomers A and B are introduced into the plasma reactor, and plasma discharge occurs. The hydrophilic coating is formed by plasma polymerization on the surface of the substrate.

[0030] or,

[0031] A substrate is provided and placed in a plasma reactor. First, the gaseous form of monomer B is introduced into the plasma reactor, and plasma discharge occurs. Plasma polymerization forms a plasma-polymerized coating of monomer B on the surface of the substrate. Then, the gaseous form of monomer A is introduced into the plasma reactor, and plasma discharge occurs. A plasma-polymerized coating of monomer A is formed on the plasma-polymerized coating of monomer B, thus obtaining the hydrophilic coating.

[0032] Optionally, the plasma discharge is a pulsed plasma discharge, wherein the pulse power is 10W to 300W, the pulse frequency is 10 to 500Hz, the pulse duty cycle is 20% to 90%, and the discharge time of the pulse output is 30s to 36000s.

[0033] A device having at least a portion of its surface covered by the hydrophilic coating described above.

[0034] The hydrophilic coating of this invention is formed by plasma polymerization of a substrate with an amino group (hydrophilic monomer A) and an epoxy group (silane monomer B) on the surface of the substrate, or by plasma polymerization of the substrate with monomer B and monomer A in succession. The hydrophilic coating has excellent hydrophilicity and light transmittance, as well as excellent wear resistance. Detailed Implementation

[0035] In some specific embodiments of the present invention, the hydrophilic coating is formed by plasma polymerization of monomers A and B on the surface of the substrate. In other specific embodiments, the substrate first contacts plasma of monomer B to form a plasma-polymerized coating of monomer B on the surface of the substrate, and then contacts plasma of monomer A to form a plasma-polymerized coating of monomer A on the plasma-polymerized coating of monomer B. The hydrophilic coating is a composite coating consisting of the plasma-polymerized coating of monomer B and the plasma-polymerized coating of monomer A.

[0036] Wherein, monomer A simultaneously contains an imino group, and at least one of a hydroxyl, carboxyl, or amino group;

[0037] The structure of monomer B is shown in equation (1) below.

[0038]

[0039] In equation (1), R4 and R5 are independently selected from hydrogen atoms, C1-C atoms, and C5, respectively. 10 Alkyl, C1-C 10 Substituted alkyl groups, C1-C 10 alkoxy or C1-C 10 The substituted alkoxy group, R6 is C1-C 10 Alkyl, C1-C 10 Substituted alkyl groups, C1-C 10 alkoxy or C1-C 10 The substituted alkoxy group is L, which is the linking moiety, and Z is the oxocyclic alkyl group.

[0040] In some specific embodiments of the hydrophilic coating of the present invention, the structure of monomer A is shown in formula (2) below.

[0041] R2-NH-R1-X1 (2)

[0042] In equation (2), R1 is C1-C 10 alkylene or C1-C 10 Substituted alkylene groups, where R2 is a hydrogen atom, C1-C 10 Alkyl, C1-C 10 The substituted alkyl group or the group with the structure shown in formula (3) below, where X1 is a hydroxyl or amino group;

[0043] X2-R3-* (3)

[0044] In equation (3), R3 is C1-C 10 alkylene or C1-C 10 The substituted alkylene group, X2 is a hydroxyl, carboxyl or amino group.

[0045] In the hydrophilic coating of the specific embodiments of the present invention, the monomer A having at least one of imino and hydroxyl, carboxyl or amino groups means that the monomer A has an imino group while having at least one of hydroxyl, carboxyl or amino groups.

[0046] In some embodiments of the hydrophilic coating of the present invention, the alkyl group is a straight-chain alkyl group, and in other embodiments, the alkyl group is a branched alkyl group, such as an alkyl group with branches such as methyl or ethyl.

[0047] In the hydrophilic coating of the present invention, the substituted alkyl group refers to an alkyl group with a substituent. The substituent can be a commonly used substituent group, such as a halogen atom, alkoxy group, ester group, amino group, or hydroxyl group. Considering the hydrophilicity, in some specific embodiments, the substituent of the substituted alkyl group is a hydroxyl group, an amino group, or a carboxyl group.

[0048] In some embodiments of the hydrophilic coating of the present invention, the alkylene group is a straight-chain alkylene group, and in other embodiments, the alkylene group is a branched alkylene group, such as an alkylene group with branches such as methyl or ethyl.

[0049] In the hydrophilic coating of the present invention, the substituted alkylene refers to an alkylene with a substituent. The substituent can be a commonly used substituent group, such as a halogen atom, ester group, amino group, or hydroxyl group. Considering hydrophilicity, in some specific embodiments, the substituent of the substituted alkylene is a hydroxyl, amino, or carboxyl group.

[0050] In the hydrophilic coating of the present invention, the substituted alkene oxide refers to an alkene oxide with a substituent. The substituent can be a commonly used substituent group, such as a halogen atom, ester group, amino group, or hydroxyl group. Considering hydrophilicity, in some specific embodiments, the substituent of the substituted alkylene oxide is a hydroxyl group, an amino group, or a carboxyl group.

[0051] In some embodiments of the hydrophilic coating of the present invention, R1 is selected from C1-C4 alkylene groups, specifically, for example, methylene, ethylene, propylene, or butylene. In some embodiments, R1 is selected from C1-C4 substituted alkylene groups, and R3 is selected from C1-C4 alkylene groups, specifically, for example, methylene, ethylene, propylene, or butylene. In some embodiments, R3 is selected from C1-C4 substituted alkylene groups.

[0052] In some embodiments of the hydrophilic coating of the present invention, R2 is selected from C1-C4 alkyl groups, specifically, for example, methylene, ethylene, propylene, or butylene. In other embodiments, R2 is selected from C1-C4 substituted alkyl groups.

[0053] In some specific embodiments of the hydrophilic coating of the present invention, the monomer A is ethanolamine, diethanolamine, N1-(2-methoxyethyl)-1,3-propanediamine, aziridine-3-ol, diisopropanolamine, sarcosine, 2-butanoethanol, hydroxyethyl ethylenediamine, N-(2-hydroxyethyl)-1,3-propanediamine, N-methyl-2-hydroxyethylamine, iminodiacetic acid, or 2-(ethylamino)prop-1-ol.

[0054] In some specific embodiments of the hydrophilic coating of the present invention, R4 and R5 are independently selected from C1-C4 alkoxy groups, and R6 is a C1-C4 alkoxy group or a C1-C4 alkyl group. The C1-C4 alkoxy groups are specifically, for example, methoxy, ethoxy, propoxy, or butoxy groups, and the C1-C4 alkyl groups are specifically, for example, methyl, ethyl, propyl, or butyl groups.

[0055] In some specific embodiments of the hydrophilic coating of the present invention, L is C1-C. 10 The alkylene group, in some specific embodiments, has L as a C1-C4 alkylene group, specifically for example, methylene, ethylene, propylene, or butylene, and in some specific embodiments, L is C1-C4. 10 The alkeneoxy group, the C1-C 10 The alkeneoxy group refers to C1-C 10 The alkylene group has at least one carbon atom bonded to an oxygen atom, and in some specific embodiments, L is a C1-C4 alkene group.

[0056] In the hydrophilic coating of this invention, Z is an oxetane group. In some embodiments, the oxetane group is a monooxetane group, such as epoxy, oxetane butyl, oxetane pentyl, etc. In some embodiments, the oxetane group is an oxetane group having two or more oxygen atoms, such as 1,3-dioxolane. In some embodiments, the oxetane group is an oxetane bicyclic group, such as 7-oxetane [4.1.0]heptyl.

[0057] In some specific embodiments of the hydrophilic coating of the present invention, the monomer B is 3-(2,3-epoxypropoxy)propyltrimethoxysilane, epoxybutyltrimethoxysilane, or 3-glycidyl etheroxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, or 3-glycidyl etheroxysilane. At least one of the following: propyltriethoxysilane, 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane, triethoxy-1-methyl-2-(epoxyethoxy)ethylsilane, trimethoxy-7-oxabicyclo[4.1.0]hept-3-ylsilane, 10-epoxyethane-2-decyltrimethoxysilane, 6,6-bis(2-methoxyethoxy)epoxyethane-11-yl-2,5,10-trioxa-6-siladecane (CAS No.:17907-81-2), [3-(1,3-dioxolane-4-ylmethoxy)propyl]trimethoxysilane, or 3-(trimethoxysilyl)propyl glycidyl ether.

[0058] In some specific embodiments of the hydrophilic coating of the present invention, the molar ratio of monomer A to monomer B is 1:1 to 1:5, for example, it can be 1:1, 1:2, 1:3, 1:4 or 1:5, etc.

[0059] In some embodiments of the hydrophilic coating of this invention, the substrate is made of metal, ceramic, plastic, glass, electronic equipment, or optical instruments; in others, the substrate is made of glass. In some embodiments, the substrate is a transparent material, specifically for example, lenses for eyeglasses, goggles, laser safety glasses, telescopes and lenses for various camera devices, observation windows for various machines, sports diving masks, bathroom glass, chemical or biological protective masks, vehicle windshields and rearview mirrors, bomb disposal protective equipment, helmets, solar panels, observation windows for measuring instruments, glass covers, and glass walls for greenhouses. The hydrophilic coating of this invention possesses both excellent light transmittance and anti-fogging capabilities, as well as excellent wear resistance and scratch resistance, making it particularly suitable for lenses made of various glass substrates.

[0060] In some specific embodiments of the hydrophilic coating of the present invention, the light transmittance of the hydrophilic coating is above 90%.

[0061] In some specific embodiments of the hydrophilic coating of the present invention, the hydrophilic coating has excellent wear resistance and hydrophilicity. The water contact angle of the hydrophilic coating, measured according to GB / T 30447-2013, is below 10°. When the hydrophilic coating is rubbed 200 times with an alcohol-soaked cotton cloth with a thread length of 4cm and a speed of 40r / min under a 10N load, the measured water contact angle remains below 10°, and the change in water contact angle before and after rubbing is no greater than 2°. In some specific embodiments, the change in water contact angle before and after rubbing is no greater than 1°.

[0062] In some specific embodiments of the hydrophilic coating of this invention, the thickness of the coating is 1-1000 nm, specifically, for example, 1 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, etc. In some specific embodiments, as an ultrathin transparent nano-coating, the thickness of the coating is 20-200 nm.

[0063] The present invention also provides a method for preparing the above-described hydrophilic coating. In some specific embodiments, the method for preparing the hydrophilic coating includes the following steps: providing a substrate, placing the substrate in a plasma reactor, introducing the gaseous monomers A and B into the plasma reactor, performing plasma discharge, and plasma polymerization on the surface of the substrate to form the hydrophilic coating; in some specific embodiments, the method for preparing the hydrophilic coating includes the following steps: providing a substrate, placing the substrate in a plasma reactor, first introducing the gaseous monomer B into the plasma reactor, performing plasma discharge, and plasma polymerization on the surface of the substrate to form a plasma-polymerized coating of monomer B, then introducing the gaseous monomer A into the plasma reactor, performing plasma discharge, and forming a plasma-polymerized coating of monomer A on the plasma-polymerized coating of monomer B, thereby obtaining the hydrophilic coating.

[0064] The preparation method of the hydrophilic coating according to a specific embodiment of the present invention, wherein monomer A, monomer B, substrate, etc. are described as above.

[0065] The method for preparing the hydrophilic coating according to specific embodiments of the present invention, in order to further enhance the adhesion between the plasma coating and the substrate, in some specific embodiments, pre-treats the substrate with plasma before coating. Specific pre-treatment methods include, for example, continuous discharge pre-treatment in an inert gas atmosphere with a discharge power of 100-600W and a discharge time of 60-600s, or pulsed discharge pre-treatment with a pulse duty cycle of 0.1-70%, a pulse frequency of 10-500Hz, a discharge power of 10-500W, and a discharge time of 60-600s. In other specific embodiments, the substrate is pre-treated with heat, oxygen, or high-energy radiation before coating.

[0066] In some specific embodiments of the hydrophilic coating preparation method of this invention, the monomer flow rate is 10-2400 μL / min, specifically for example, 10 μL / min, 50 μL / min, 100 μL / min, 200 μL / min, 300 μL / min, 500 μL / min, 1000 μL / min, 1500 μL / min, 2000 μL / min, or 2400 μL / min, etc.; the temperature inside the chamber is controlled at 20℃-80℃, specifically for example, 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, or 80℃, etc.; the monomer vaporization temperature is 50℃-120℃, specifically for example, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, or 120℃, etc., and vaporization occurs under vacuum conditions.

[0067] In some specific embodiments of the hydrophilic coating preparation method of the present invention, the plasma is a continuous plasma, which is generated by applying a continuous voltage discharge. The discharge power is 10-300W, specifically, for example, 10W, 50W, 100W, 150W, 200W, 250W or 300W, and the discharge time is 60-600s, specifically, for example, 60s, 100s, 200s, 300s, 400s, 500s or 600s, etc. In some specific embodiments, the plasma is pulsed plasma, which is generated by applying a pulsed voltage discharge. The pulse power is 10W-400W, specifically, for example, 10W, 50W, 100W, 150W, 200W, 250W, 300W, 350W, or 400W, etc.; the pulse frequency is 10Hz-500Hz, specifically, for example, 10Hz, 15Hz, 20Hz, 25Hz, 30Hz, or 35Hz. The pulse frequency can be 40Hz, 45Hz, 50Hz, 100Hz, 200Hz, 300Hz, 400Hz, or 500Hz, etc.; the pulse duty cycle is 0.1% to 70%, specifically for example, 0.1%, 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or 70%, etc.; the plasma discharge time is 600s-7200s, specifically for example, 600s, 700s, 800s, 900s, 1000s, 2000s, 3000s, 4000s, 5000s, 6000s, or 7000s, etc.

[0068] In some specific embodiments of the hydrophilic coating preparation method of the present invention, the plasma discharge method can be any existing discharge method, such as electrodeless discharge (e.g., radio frequency inductively coupled discharge, microwave discharge), single-electrode discharge (e.g., corona discharge, plasma jet formed by unipolar discharge), dual-electrode discharge (e.g., dielectric barrier discharge, radio frequency glow discharge of exposed electrodes), and multi-electrode discharge (e.g., discharge using a floating electrode as the third electrode).

[0069] A specific embodiment of the present invention also provides a device having at least a portion of its surface with the hydrophilic coating described above. In some specific embodiments, the hydrophilic coating described above is deposited on a portion or all of the surface of the device.

[0070] The present disclosure will be further illustrated by specific embodiments below.

[0071] Example

[0072] Test Method Description

[0073] Coating thickness test: The coating thickness was measured using a Filmetrics F20-UV film thickness meter.

[0074] Coating transmittance test (T(%)): The transmittance was measured using a Perkin-Elmer-Lambda 950 UV-Vis spectrophotometer.

[0075] Coating water contact angle: tested according to GB / T 30447-2013 standard.

[0076] Coating anti-fogging performance test: Place the sample on a 95℃ constant temperature water bath with the coated surface facing the water vapor, and the distance between the water surface and the coated surface is 5cm. Observe whether fogging occurs after 10 minutes. If a uniform water film is formed and the field of vision is clear, it is judged as OK; if fogging occurs, it is judged as NG.

[0077] Coating abrasion resistance test: A linear abrasion tester manufactured by Taber was used. The load was 10N, the friction medium was cotton cloth soaked in alcohol, the thread length was 4cm, the speed was 40r / min, and after 200 abrasion cycles, the water contact angle of the coating was tested.

[0078] Example 1

[0079] A transparent glass plate (75 mm long, 26 mm wide, and 1 mm thick) was placed in a 500 L plasma reaction chamber. The chamber was continuously evacuated to a vacuum level of 80 mTorr. The internal temperature of the chamber was 45 °C. Helium gas was introduced at a flow rate of 40 sccm.

[0080] Maintain the cavity pressure at 80 mTorr and the helium flow rate at 40 sccm, turn on the radio frequency plasma discharge, the radio frequency energy output mode is continuous discharge, the discharge time is 300s, the discharge power is 300w, and pre-treat the transparent glass plate.

[0081] After pretreatment, 3-(2,3-epoxypropoxy)propyltrimethoxysilane and diethanolamine were mixed at a mass ratio of 2.3:1 and stirred at room temperature for 10 minutes until homogeneous. The mixture was then loaded into the equipment feed tank and vaporized at 110°C before being introduced into the plasma reaction chamber. The chamber pressure was maintained at 80 mTorr, the helium flow rate was maintained at 40 sccm, and the monomer flow rate was maintained at 100 μL / min. Radio frequency plasma discharge was activated, with the radio frequency energy output mode being pulsed, the discharge time being 1800 s, the discharge power being 80 W, the pulse frequency being 50 Hz, and the pulse duty cycle being 45%, forming a hydrophilic coating.

[0082] After the coating preparation is completed, air is introduced to restore the reaction chamber to normal pressure, the chamber is opened, and the transparent glass plate is removed.

[0083] The hydrophilic coating was tested for coating thickness, light transmittance, anti-fogging performance and abrasion resistance. The test results are listed in Table 1 below.

[0084] Example 2

[0085] Except for replacing the mixing of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and diethanolamine in a mass ratio of 2.3:1 with the mixing of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and diethanolamine in a mass ratio of 1:1, everything else is the same as in Example 1.

[0086] The hydrophilic coating was tested for coating thickness, light transmittance, anti-fogging performance and abrasion resistance. The test results are listed in Table 1 below.

[0087] Example 3

[0088] Except for replacing diethanolamine with hydroxyethyl ethylenediamine, everything else is the same as in Example 1.

[0089] The hydrophilic coating was tested for coating thickness, light transmittance, anti-fogging performance and abrasion resistance. The test results are listed in Table 1 below.

[0090] Example 4

[0091] Except for replacing the mixing of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and diethanolamine in a mass ratio of 2.3:1 with the mixing of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and diethanolamine in a mass ratio of 2.6:1, everything else is the same as in Example 1.

[0092] The hydrophilic coating was tested for coating thickness, light transmittance, anti-fogging performance and abrasion resistance. The test results are listed in Table 1 below.

[0093] Example 5

[0094] Except for replacing the mixture of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and diethanolamine in a mass ratio of 2.3:1 with the mixture of butyltrimethoxysilane and N-(2-hydroxyethyl)-1,3-propanediamine in a mass ratio of 1.6:1, everything else is the same as in Example 1.

[0095] The hydrophilic coating was tested for coating thickness, light transmittance, anti-fogging performance and abrasion resistance. The test results are listed in Table 1 below.

[0096] Example 6

[0097] Except for replacing the mixing of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and diethanolamine in a mass ratio of 2.3:1 with the mixing of 3-glycidyl etheroxypropylmethyldiethoxysilane and ethanolamine in a mass ratio of 2:1, everything else is the same as in Example 1.

[0098] The hydrophilic coating was tested for coating thickness, light transmittance, anti-fogging performance and abrasion resistance. The test results are listed in Table 1 below.

[0099] Example 7

[0100] A transparent glass plate (75 mm long, 26 mm wide, and 1 mm thick) was placed in a 500 L plasma reaction chamber. The chamber was continuously evacuated to a vacuum level of 80 mTorr. The internal temperature of the chamber was 45 °C. Helium gas was introduced at a flow rate of 40 sccm.

[0101] Maintain the cavity pressure at 80 mTorr and the helium flow rate at 40 sccm, turn on the radio frequency plasma discharge, the radio frequency energy output mode is continuous discharge, the discharge time is 300s, the discharge power is 300w, and pre-treat the transparent glass plate.

[0102] After pretreatment, 3-(2,3-epoxypropoxy)propyltrimethoxysilane and diethanolamine were respectively loaded into the feed tanks of two devices. The monomer 3-(2,3-epoxypropoxy)propyltrimethoxysilane was vaporized at 110℃ and then introduced into the plasma reaction chamber. The chamber pressure was maintained at 80 mTorr, the helium flow rate was maintained at 40 sccm, and the monomer flow rate was maintained at 100 μL / min. Radio frequency plasma discharge was started. The radio frequency energy output mode was pulsed, the discharge power was 80 W, the pulse frequency was 50 Hz, the pulse duty cycle was 45%, and the discharge time was 1800 s. After that, the introduction of monomer 3-(2,3-epoxypropoxy)propyltrimethoxysilane was stopped, and the monomer diethanolamine was vaporized at 110℃ and then introduced into the plasma reaction chamber. The discharge time was 3600 s, forming a two-layer composite hydrophilic coating.

[0103] After the coating preparation is completed, air is introduced to restore the reaction chamber to normal pressure, the chamber is opened, and the transparent glass plate is removed.

[0104] The hydrophilic coating was tested for coating thickness, light transmittance, anti-fogging performance and abrasion resistance. The test results are listed in Table 1 below.

[0105] Comparative Example 1

[0106] Transparent glass plate (length: 75mm, width: 26mm, thickness: 1mm).

[0107] Comparative Example 2

[0108] Except for replacing the mixed monomers 3-(2,3-epoxypropoxy)propyltrimethoxysilane and diethanolamine in a mass ratio of 2.3:1 with 3-(2,3-epoxypropoxy)propyltrimethoxysilane, everything else is the same as in Example 1.

[0109] The hydrophilic coating was tested for coating thickness, light transmittance, anti-fogging performance and abrasion resistance. The test results are listed in Table 1 below.

[0110] Comparative Example 3

[0111] Except for replacing the mixed monomers 3-(2,3-epoxypropoxy)propyltrimethoxysilane and diethanolamine in a mass ratio of 2.3:1 with diethanolamine, everything else is the same as in Example 1.

[0112] The hydrophilic coating was tested for coating thickness, light transmittance, anti-fogging performance and abrasion resistance. The test results are listed in Table 1 below.

[0113] Comparative Example 4

[0114] Clean the transparent glass plate (75mm long, 26mm wide, 1mm thick) with alcohol and let it dry. Then place it in a plasma cleaning device for cleaning and activation for 10 minutes.

[0115] Weigh 23g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane reagent and 10g of diethanolamine reagent and mix them in a beaker. Stir and heat at 60℃ for 4h. Then add 8g of H2O, 20g of ethanol, and adjust the pH to 1. Continue stirring at 60℃ for 4h to prepare the coating solution.

[0116] The coating solution is applied to the surface of the transparent glass plate using a dip-coating method, and the transparent glass plate is cured in an oven at 100°C for 2 hours to obtain a hydrophilic coating.

[0117] The hydrophilic coating was tested for coating thickness, light transmittance, anti-fogging performance and abrasion resistance. The test results are listed in Table 1 below.

[0118] Table 1. Test results of Examples 1-7 and Comparative Examples 1-4

[0119]

[0120] According to the test results in Table 1 above, compared with the glass plate of Comparative Example 1, the glass plates with hydrophilic coatings in Examples 1-7 have a hydrophilic effect and can effectively achieve anti-fogging. Comparing the results of Example 1 with Comparative Examples 2 and 3, it can be seen that the plasma coating of epoxy silane is not hydrophilic, but the plasma hydrophilic coating prepared together with the hydrophilic monomer of diethanolamine does not have its hydrophilicity affected, but its abrasion resistance is greatly improved. Comparing the results of Example 7 with Comparative Examples 2 and 3, it can be seen that using the plasma coating of epoxy silane as an intermediate coating can effectively and significantly improve the abrasion resistance of the plasma hydrophilic coating of diethanolamine. Comparing the results of Example 1 with Comparative Example 4, it can be seen that in Comparative Example 4, after hydrolysis, the coating combines with the glass surface using hydroxyl groups and is then thermo-cured to form a coating with a water contact angle of 50° and no anti-fogging effect. This indicates that plasma coating technology can form a denser coating with a much greater number of hydrophilic groups on the surface than coatings obtained by conventional chemical methods, thus enabling the preparation of excellent hydrophilic anti-fogging coatings.

[0121] While the above disclosure is provided, it is not limited thereto. Any person skilled in the art may make various alterations and modifications without departing from the spirit and scope of this disclosure; therefore, the scope of protection of this disclosure shall be determined by the scope defined in the claims.

Claims

1. A hydrophilic coating, characterized in that, The hydrophilic coating is a coating formed by plasma polymerization on the surface of the substrate after the substrate comes into contact with plasma containing monomer A and monomer B, or the hydrophilic coating is a composite coating formed by the substrate coming into contact with plasma of monomer B and plasma of monomer A in succession. Wherein, monomer A simultaneously contains an imino group, and at least one of a hydroxyl, carboxyl, or amino group; The structure of monomer B is shown in equation (1) below. In equation (1), R4 and R5 are independently selected from hydrogen atoms, C1-C atoms, and C5, respectively. 10 Alkyl, C1-C 10 Substituted alkyl groups, C1-C 10 alkoxy or C1-C 10 The substituted alkoxy group, R6 is C1-C 10 Alkyl, C1-C 10 Substituted alkyl groups, C1-C 10 alkoxy or C1-C 10 The substituted alkoxy group is L, the linking moiety is Z, and the oxocyclic alkyl group is Z.

2. The hydrophilic coating according to claim 1, characterized in that, The structure of monomer A is shown in equation (2) below. R2-NH-R1-X1 (2) In equation (2), R1 is C1-C 10 alkylene or C1-C 10 Substituted alkylene groups, where R2 is a hydrogen atom, C1-C 10 Alkyl, C1-C 10 The substituted alkyl group or the group with the structure shown in formula (3) below, where X1 is a hydroxyl, carboxyl or amino group; X2-R3-* (3) In equation (3), R3 is C1-C 10 alkylene or C1-C 10 The substituted alkylene group, X2 is a hydroxyl, carboxyl or amino group.

3. The hydrophilic coating according to claim 2, characterized in that, R1 is selected from C1-C4 alkylene or C1-C4 substituted alkylene, and R3 is selected from C1-C4 alkylene or C1-C4 substituted alkylene.

4. The hydrophilic coating according to claim 1, characterized in that, The monomer A is ethanolamine, diethanolamine, N1-(2-methoxyethyl)-1,3-propanediamine, aziridine-3-ol, diisopropanolamine, sarcosine, 2-butanoethanol, hydroxyethyl ethylenediamine, N-(2-hydroxyethyl)-1,3-propanediamine, N-methyl-2-hydroxyethylamine, iminodiacetic acid, or 2-(ethylamino)prop-1-ol.

5. The hydrophilic coating according to claim 1, characterized in that, R4 and R5 are each independently selected from C1-C4 alkoxy groups, R6 is a C1-C4 alkoxy group or a C1-C4 alkyl group, and Z is an epoxy group.

6. The hydrophilic coating according to claim 5, characterized in that, R4 and R5 are each independently selected from methoxy or ethoxy, and R6 is methoxy, ethoxy, methyl, or ethyl.

7. The hydrophilic coating according to claim 1, characterized in that, The L is C1-C 10 alkylene or alkeneoxy groups.

8. The hydrophilic coating according to claim 1, characterized in that, The monomer B is 3-(2,3-epoxypropoxy)propyltrimethoxysilane, epoxybutyltrimethoxysilane, 3-glycidyl etheroxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, 3-glycidyl etheroxypropyltriethoxysilane, 3-[(2,3)-epoxypropoxy]propylmethyldiethoxysilane, triethoxy-1 At least one of the following: methyl-2-(ethylene oxide methoxy)ethylsilane, trimethoxy-7-oxabicyclo[4.1.0]hept-3-ylsilane, 10-ethylene oxide-2-decyltrimethoxysilane, 6,6-bis(2-methoxyethoxy)ethylene oxide-11-yl-2,5,10-trioxa-6-silane undecane, [3-(1,3-dioxolane-4-ylmethoxy)propyl]trimethoxysilane, or 3-(trimethoxysilyl)propyl glycidyl ether.

9. The hydrophilic coating according to claim 1, characterized in that, The molar ratio of monomer A to monomer B is 1:1 to 1:

5.

10. The hydrophilic coating according to claim 1, characterized in that, The substrate can be an optical instrument, metal, ceramic, plastic, glass, or electronic device.

11. The hydrophilic coating according to claim 1, characterized in that, The light transmittance of the hydrophilic coating is above 90%.

12. The hydrophilic coating according to claim 1, characterized in that, The water contact angle measured by the hydrophilic coating is below 10°.

13. The hydrophilic coating according to claim 1, characterized in that, The hydrophilic coating was rubbed 200 times with an alcohol-soaked cotton cloth at a thread length of 4 cm and a speed of 40 r / min under a 10 N load, and the change in the water contact angle was measured to be no greater than 2°.

14. A method for preparing a hydrophilic coating as described in any one of claims 1-13, characterized in that, Includes the following steps: A substrate is provided, which is placed in a plasma reactor. The gaseous monomers A and B are introduced into the plasma reactor, and plasma discharge occurs. The hydrophilic coating is formed by plasma polymerization on the surface of the substrate. or, A substrate is provided and placed in a plasma reactor. First, the gaseous form of monomer B is introduced into the plasma reactor, and plasma discharge occurs. Plasma polymerization is performed on the surface of the substrate to form a plasma-polymerized coating of monomer B. Then, the gaseous form of monomer A is introduced into the plasma reactor, and plasma discharge occurs. A plasma-polymerized coating of monomer A is formed on the plasma-polymerized coating of monomer B, thus obtaining the hydrophilic coating.

15. The method for preparing the hydrophilic coating according to claim 14, characterized in that, The plasma discharge is a pulsed plasma discharge, wherein the pulse power is 10W to 300W, the pulse frequency is 10 to 500Hz, the pulse duty cycle is 20% to 90%, and the discharge time of the pulse output is 30s to 36000s.

16. A device, characterized in that, At least a portion of the surface of the device has the hydrophilic coating as described in any one of claims 1-13.

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