A superhydrophilic anti-fog coating, its preparation method and application

Abstract

The present invention provides a superhydrophilic anti-fog coating, a preparation method thereof and an application, belonging to the field of coatings. The method for preparing the superhydrophilic anti-fog coating comprises the following steps: (1) preparation of a prepolymer; (2) preparation of the superhydrophilic anti-fog coating. The superhydrophilic anti-fog coating prepared by the preparation method provided by the present invention, after being coated to obtain a superhydrophilic coating layer, has excellent superhydrophilicity, high adhesion, self-healing property and high visible light transmittance, and can be effectively used in the fields of spectacle lenses, chemical or biological protection masks, vehicle windshields, solar panels, etc.

Description

Technical Field

[0001] The present invention belongs to the field of coatings, and particularly relates to a superhydrophilic anti-fog coating, a preparation method thereof, and an application thereof. Background Art

[0002] Nowadays, transparent materials such as silicate glass, polycarbonate, polymethyl methacrylate, and polyethylene have been widely used in various fields of people's daily production and life, such as spectacle lenses, chemical or biological protection masks, vehicle windshields, solar panels, etc. However, the atomization phenomenon of water vapor seriously affects the use effect of the above transparent substrates. How to overcome the atomization of water vapor on the surface of transparent substrates has become a research hotspot in the field of anti-fog materials. Changing the chemical composition or microstructure of the substrate surface to improve the wetting performance of the substrate surface is a common anti-fog strategy. Among them, the method of coating a hydrophilic coating on the substrate surface so that the fog droplets can spread to form a water film when attached to the coating surface can avoid the refraction and reflection of sunlight caused by the formation of fog droplets, and solve the inconvenience and potential safety hazards brought about by the atomization of the transparent material surface. In recent years, although a variety of anti-fog coatings have been developed based on the above method, they still face the following challenges: (1) Loss of anti-fog performance after being in a humid environment for a long time or being washed by rain; (2) Low visible light transmittance; (3) The coating is damaged after being subjected to external force and loses the self-healing ability and anti-fog performance. Therefore, how to design a superhydrophilic anti-fog coating with high transmittance, long life, and self-healing ability is still an urgent problem to be solved. Summary of the Invention

[0003] The purpose of the present invention is to provide a superhydrophilic anti-fog coating, a preparation method thereof, and an application thereof, which are used to solve the problems such as the atomization of water vapor on the surface of transparent substrates and low visible light transmittance existing in the prior art.

[0004] In order to achieve the above purpose or other purposes, the present invention is realized by the following technical solutions.

[0005] A method for preparing a superhydrophilic anti-fog coating, comprising the following steps: (1) Preparation of a prepolymer; (2) Preparation of the superhydrophilic anti-fog coating.

[0006] Specifically, it comprises the following steps:

[0007] (1) Preparation of a prepolymer: Mix an initiator and an emulsifier, add solvent I and stir. After stirring evenly, a mixed solution is obtained; Take acrylic monomers and methacrylate monomers and mix them evenly, then drop them into the above mixed solution under stirring. After the dropping is completed, react under nitrogen protection, and after the reaction is completed, perform a cooling treatment to obtain a prepolymer;

[0008] (2) Preparation of superhydrophilic antifogging coating: Take ionic monomers and initiators, add solvent II, stir until dissolved, then dropwise add the prepolymer obtained in step (1) to the solution. After the addition is completed, stir evenly, carry out a heating reaction under nitrogen protection, and perform a cooling treatment after the reaction is completed to obtain the superhydrophilic antifogging coating.

[0009] Further, the initiator is selected from persulfate compounds. Preferably, the initiator is selected from one or more of potassium persulfate, sodium persulfate, and ammonium persulfate;

[0010] Further, the emulsifier is selected from non-ionic emulsifiers. Preferably, the emulsifier is selected from one or more of Tween-80, OP-10, and AEO-3;

[0011] Further, the solvent I is selected from one or more of water, acetonitrile, ethanol, butyl acetate, and ethyl acetate.

[0012] Further, the acrylic monomers are selected from one or more of acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, and n-butyl acrylate.

[0013] Further, the methacrylate monomers are selected from one or more of methacrylic acid, methyl methacrylate, and 2-hydroxyethyl methacrylate.

[0014] Further, the dropping rate in step (1) is 1 - 10 mL / min.

[0015] Further, the mass ratio of the initiator to the emulsifier in step (1) is (1 - 5):(5 - 10).

[0016] Further, the mass ratio of the initiator to the total amount of acrylic monomers and methacrylate monomers in step (1) is (1 - 8):(35 - 200).

[0017] Further, the mass ratio of the total amount of acrylic monomers and methacrylate monomers to the solvent in step (1) is (1 - 5):(5 - 100).

[0018] Further, the reaction temperature in step (1) is 50 - 90 °C, and the reaction time is 0.5 - 6 h.

[0019] Further, the ionic monomers in step (2) are selected from one or more of methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl dimethyl benzyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, sodium methallyl sulfonate, and sodium p-styrene sulfonate.

[0020] Further, the solvent II in step (2) is selected from one or more of water, acetonitrile, ethanol, isopropanol, and glycerol.

[0021] Further, the mass ratio of the initiator to the ionic monomer in step (2) is (1-9):(10-200).

[0022] Further, the mass ratio of the ionic monomer to the prepolymer in step (2) is (1-7):(1-120).

[0023] Further, the mass ratio of the ionic monomer to the solvent II in step (2) is (1-5):(5-10).

[0024] Further, the dropping rate of the prepolymer in step (2) is 0.5-10 mL / min.

[0025] Further, the reaction temperature in step (2) is 50-90 °C, and the reaction time is 3-24 h.

[0026] Further, after the reactions of steps (1) and (2) are completed, the cooling treatment is carried out using an ice-water bath for cooling.

[0027] The present invention also discloses a superhydrophilic anti-fog coating prepared by the above preparation method.

[0028] The present invention also protects a superhydrophilic anti-fog coating comprising the above superhydrophilic anti-fog coating.

[0029] The preparation method of the superhydrophilic anti-fog coating includes the following steps: dropping the superhydrophilic anti-fog coating into a diluent, stirring at room temperature until evenly dispersed, uniformly coating the obtained emulsion on the surface of a glass substrate, and drying to obtain the superhydrophilic anti-fog coating.

[0030] Preferably, the mass ratio of the superhydrophilic anti-fog coating to the diluent is (1-5):(1-80).

[0031] Preferably, the diluent is selected from one or more of water, acetonitrile, ethanol, isopropanol, glycerol, and butyl acetate. Preferably, the stirring speed is 500-4000 rpm. The stirring time is 0.5-2 h. The drying temperature is 45-90 °C.

[0032] Among them, the coating method can be a conventional method in the art such as spin coating or dip coating. The coating amount of the emulsion during coating is 0.1-10 g / m 2 .

[0033] The present invention also protects the application of the above superhydrophilic anti-fog coating in the fields of glasses, protective masks, windshield glass, and solar panels.

[0034] In the present invention, a multifunctional superhydrophilic resin is obtained by free radical polymerization of a monomer containing an ionic group and an acrylic acid or methacrylate monomer. The ionic structural unit provides strong hydrophilicity, and the acrylic acid or methacrylate structural unit adjusts the softness, hardness and glass transition temperature of the polymer. Moreover, the abundant hydroxyl or carboxyl groups present in the polymer chain segment can not only endow the coating with self-healing function to solve the problem that the anti-fog performance of the coating is lost due to external force damage, but also improve the adhesion between the resin and the substrate, avoiding the problem that the performance of the anti-fog coating is reduced due to long-term washing by rainwater.

[0035] In summary, the superhydrophilic anti-fog coating prepared by the preparation method provided by the present invention, and the superhydrophilic coating obtained by coating, has excellent superhydrophilicity, high adhesion, self-healing property and high visible light transmittance, and can be effectively used in the fields of spectacle lenses, chemical or biological protection masks, vehicle windshields, solar panels, etc. Description of the Drawings

[0036] Figure 1 It is the physical diagram of the hot fog test and the contact angle test results, where: a) is the physical diagram of the hot fog test of the blank glass slide; b) is the physical diagram of the hot fog test of the superhydrophilic anti-fog coating prepared in Application Example 1 of the present invention; c) is the contact angle test result of the blank glass slide; d) is the contact angle test result of the superhydrophilic anti-fog coating prepared in Application Example 1.

[0037] Figure 2 They are respectively the physical diagrams of the hot fog test and the contact angle test results of the superhydrophilic anti-fog coatings obtained in Application Examples 2 to 6 of the present invention, where: a) is the physical diagram of the hot fog test and the contact angle test result of the superhydrophilic anti-fog coating in Application Example 2; b) is the physical diagram of the hot fog test and the contact angle test result of the superhydrophilic anti-fog coating in Application Example 3; c) is the physical diagram of the hot fog test and the contact angle test result of the superhydrophilic anti-fog coating in Application Example 4; d) is the physical diagram of the hot fog test and the contact angle test result of the superhydrophilic anti-fog coating in Application Example 5; e) is the physical diagram of the hot fog test and the contact angle test result of the superhydrophilic anti-fog coating in Application Example 6.

[0038] Figure 3 They are the UV-vis spectra of the blank glass slide and the superhydrophilic anti-fog coatings prepared in Application Examples 1 to 6 of the present invention.

[0039] Figure 4 It is the physical diagram of the glass slide with the superhydrophilic anti-fog coating prepared in Application Example 1 of the present invention.

[0040] Figure 5 It is the adhesion test diagram of the superhydrophilic anti-fog coating prepared in Application Example 1 of the present invention.

[0041] Figure 6Physical photos of coated sheets at different stages of the superhydrophilic and antifogging coating prepared according to the present invention: (a) Before scratching; (b) After scratching; (c) During the hot fog experiment; (d) After the hot fog experiment.

[0042] Figure 7 Physical diagram of the hot fog test after 1 h of water flow scouring, where (a) the coated sheet coated with a commercially available antifogging coating; (b) the superhydrophilic and antifogging coating prepared in Application Example 1. Detailed implementation manners

[0043] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0044] It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. It should also be understood that the terms used in the embodiments of the present invention are for describing specific specific implementation manners, rather than for limiting the protection scope of the present invention. The test methods without specific conditions noted in the following embodiments are generally in accordance with conventional conditions or in accordance with the conditions recommended by each manufacturer.

[0045] When the embodiments give a numerical range, it should be understood that unless otherwise specified in the present invention, any value at both ends of each numerical range and any value between the two ends can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention, based on the understanding of those skilled in the art of the prior art and the description of the present invention, can also use any method, device, and material similar to or equivalent to the methods, devices, and materials described in the embodiments of the present invention to implement the present invention.

[0046] The present invention will be further described below through specific embodiments, but the present invention is not limited thereto. The specific protection scope is shown in the claims.

[0047] Example 1

[0048] Preparation of prepolymer

[0049] Add 0.7 g of ammonium persulfate initiator, 3.2 g of Tween-80 emulsifier, 300 mL of deionized water, and 180 mL of ethanol to a single-necked flask equipped with a magnetic stir bar in sequence, and then stir magnetically at room temperature for 10 min; Weigh another 20 g of n-propyl acrylate and 50 g of methacrylic acid monomer and mix them evenly. Subsequently, slowly add the mixture dropwise to the above mixed solution at a rate of 2.5 mL / min under stirring conditions. After the addition is completed, heat and react at 60 °C for 3 h under nitrogen protection. Immediately transfer to an ice-water bath for full cooling after the reaction is completed to obtain the prepolymer.

[0050] Preparation of Superhydrophilic Antifogging Coating

[0051] Add 4.0 g of methacryloyloxyethyl trimethyl ammonium chloride, 0.06 g of ammonium persulfate, 18 mL of deionized water, and 6 mL of isopropanol to a single-necked flask equipped with a magnetic stir bar in sequence, and stir at room temperature until completely dissolved. Slowly add 18 mL of the prepolymer obtained in step (1) to the above solution at a dropping rate of 3 mL / min. After the addition is completed, stir at room temperature until evenly dispersed. React at 80 °C for 8 h under nitrogen protection. Immediately cool with an ice-water bath after the reaction is completed to obtain the superhydrophilic antifogging coating with superhydrophilic antifogging function.

[0052] Example 2

[0053] Preparation of Prepolymer

[0054] Add 0.7 g of ammonium persulfate initiator, 4.5 g of Tween-80 emulsifier, 300 mL of deionized water, and 150 mL of ethanol to a single-necked flask equipped with a magnetic stir bar in sequence, and then stir magnetically at room temperature for 10 min; Weigh another 20 g of n-propyl acrylate and 45 g of methacrylic acid monomer and mix them evenly. Subsequently, slowly add the mixture dropwise to the above mixed solution at a rate of 2.5 mL / min under stirring conditions. After the addition is completed, heat and react at 65 °C for 2.5 h under nitrogen protection. Immediately transfer to an ice-water bath for full cooling after the reaction is completed to obtain the prepolymer.

[0055] Preparation of Superhydrophilic Antifogging Coating

[0056] Add 4.0 g of sodium methallyl sulfonate, 0.06 g of sodium persulfate, 18 mL of deionized water, and 6 mL of ethanol to a single-necked flask equipped with a magnetic stir bar in sequence, and stir at room temperature until completely dissolved. Slowly add 20 mL of the prepolymer obtained in step (1) to the above solution at a dropping rate of 3 mL / min. After the addition is completed, stir at room temperature until evenly dispersed. React at 70 °C for 18 h under nitrogen protection. Immediately cool with an ice-water bath after the reaction is completed to obtain the superhydrophilic antifogging coating with superhydrophilic antifogging function.

[0057] Example 3

[0058] Preparation of Prepolymer

[0059] 0.7 g of ammonium persulfate initiator, 1.5 g of Tween-80 emulsifier, 400 mL of deionized water, and 60 mL of ethanol were successively added to a single-necked flask equipped with a magnetic stir bar, and then magnetically stirred at room temperature for 10 min; another 20 g of acrylic acid and 40 g of 2-hydroxyethyl methacrylate monomers were weighed and mixed evenly, and then slowly added dropwise to the above mixed solution at a rate of 3 mL / min under stirring conditions. After the addition was completed, the reaction was carried out at 65 °C for 2 h under nitrogen protection. Immediately after the reaction was completed, it was transferred to an ice-water bath and cooled sufficiently to obtain a prepolymer.

[0060] Preparation of superhydrophilic anti-fog coating

[0061] 4.0 g of acryloyloxyethyl dimethyl benzyl ammonium chloride, 0.06 g of ammonium persulfate, 30 mL of deionized water, and 5 mL of isopropanol were successively added to a single-necked flask equipped with a magnetic stir bar and stirred at room temperature until completely dissolved. 30 mL of the prepolymer obtained in step (1) was slowly added dropwise to the above solution at a dropping rate of 3 mL / min, and after the addition was completed, it was stirred at room temperature until uniformly dispersed. The reaction was carried out at 75 °C for 12 h under nitrogen protection, and immediately after the reaction was completed, it was cooled with an ice-water bath to obtain a superhydrophilic anti-fog coating with superhydrophilic anti-fog function.

[0062] Example 4

[0063] Preparation of prepolymer

[0064] 0.5 g of potassium persulfate initiator, 2.0 g of AEO-3 emulsifier, 400 mL of deionized water, and 50 mL of ethanol were successively added to a single-necked flask equipped with a magnetic stir bar, and then magnetically stirred at room temperature for 10 min; another 2 g of ethyl acrylate and 58 g of methyl methacrylate monomers were weighed and mixed evenly, and then slowly added dropwise to the above mixed solution at a rate of 2.5 mL / min under stirring conditions. After the addition was completed, the reaction was carried out at 60 °C for 3 h under nitrogen protection. Immediately after the reaction was completed, it was transferred to an ice-water bath and cooled sufficiently to obtain a prepolymer.

[0065] Preparation of superhydrophilic anti-fog coating

[0066] 15 g of acryloyloxyethyl trimethyl ammonium chloride, 0.3 g of ammonium persulfate, 80 mL of deionized water, and 10 mL of isopropanol were successively added to a single-necked flask equipped with a magnetic stir bar and stirred at room temperature until completely dissolved. 80 mL of the prepolymer obtained in step (1) was slowly added dropwise to the above solution at a dropping rate of 8 mL / min, and after the addition was completed, it was stirred at room temperature until uniformly dispersed. The reaction was carried out at 80 °C for 8 h under nitrogen protection, and immediately after the reaction was completed, it was cooled with an ice-water bath to obtain a superhydrophilic anti-fog coating with superhydrophilic anti-fog function.

[0067] Example 5

[0068] Preparation of Prepolymer

[0069] Add 0.7 g of ammonium persulfate initiator, 1.8 g of AEO-3 emulsifier, and 400 mL of deionized water into a single-necked flask equipped with a magnetic stir bar in sequence, and then stir magnetically at room temperature for 10 min; separately weigh 30 g of acrylic acid and 30 g of hydroxyethyl methacrylate monomers and mix them evenly, and then slowly add them dropwise to the above mixed solution at a rate of 5 mL / min under stirring conditions. After the addition is completed, heat and react at 60 °C for 1.0 h under nitrogen protection. Immediately transfer it to an ice-water bath for sufficient cooling after the reaction is completed, and thus obtain the prepolymer.

[0070] Preparation of Superhydrophilic Antifogging Coating

[0071] Add 15 g of sodium p-styrenesulfonate, 0.3 g of ammonium persulfate, 70 mL of deionized water, and 6 mL of glycerol into a single-necked flask equipped with a magnetic stir bar in sequence, and stir at room temperature until completely dissolved. Slowly add 60 mL of the prepolymer obtained in step (1) to the above solution at a dropping rate of 5 mL / min, and stir at room temperature until evenly dispersed after the addition is completed. React at 65 °C for 20 h under nitrogen protection, and immediately cool it with an ice-water bath after the reaction is completed, and thus obtain the superhydrophilic antifogging coating with superhydrophilic antifogging function.

[0072] Example 6

[0073] Preparation of Prepolymer

[0074] Add 0.7 g of ammonium persulfate initiator, 1.5 g of OP-10 emulsifier, and 300 mL of deionized water into a single-necked flask equipped with a magnetic stir bar in sequence, and then stir magnetically at room temperature for 10 min; separately weigh 25 g of methyl acrylate and 50 g of methyl methacrylate monomers and mix them evenly, and then slowly add them dropwise to the above mixed solution at a rate of 4 mL / min under stirring conditions. After the addition is completed, heat and react at 60 °C for 1.5 h under nitrogen protection. Immediately transfer it to an ice-water bath for sufficient cooling after the reaction is completed, and thus obtain the prepolymer.

[0075] Preparation of Superhydrophilic Antifogging Coating

[0076] Add 4 g of acryloyloxyethyl dimethylbenzyl ammonium chloride, 0.08 g of ammonium persulfate, 20 mL of deionized water, and 3 mL of isopropanol into a single-necked flask equipped with a magnetic stir bar in sequence, and stir at room temperature until completely dissolved. Slowly add 25 mL of the prepolymer obtained in step (1) to the above solution at a dropping rate of 3 mL / min, and stir at room temperature until evenly dispersed after the addition is completed. React at 70 °C for 18 h under nitrogen protection, and immediately cool it with an ice-water bath after the reaction is completed, and thus obtain the superhydrophilic antifogging coating with superhydrophilic antifogging function.

[0077] Example 7

[0078] Preparation of Prepolymer

[0079] Add 0.8 g of ammonium persulfate initiator, 1.2 g of OP-10 emulsifier, and 350 mL of deionized water into a single-necked flask equipped with a magnetic stir bar in sequence, and then stir magnetically at room temperature for 10 min; separately weigh 30 g of n-propyl acrylate and 55 g of 2-hydroxyethyl methacrylate monomers and mix them evenly, and then slowly add them dropwise to the above mixed solution at a rate of 4 mL / min under stirring conditions. After the addition is completed, heat and react at 65 °C for 2 h under nitrogen protection. Immediately transfer to an ice-water bath for sufficient cooling after the reaction is completed, and the prepolymer is obtained.

[0080] Preparation of Superhydrophilic Antifogging Coating

[0081] Add 5 g of sodium methallylsulfonate, 0.2 g of ammonium persulfate, 33 mL of deionized water, and 6 mL of isopropanol into a single-necked flask equipped with a magnetic stir bar in sequence, and stir at room temperature until completely dissolved. Slowly add 22 mL of the prepolymer obtained in step (1) to the above solution at a dropping rate of 3 mL / min, and stir at room temperature until evenly dispersed after the addition is completed. React at 70 °C for 12 h under nitrogen protection, and immediately cool with an ice-water bath after the reaction is completed to obtain a superhydrophilic antifogging coating with superhydrophilic antifogging function.

[0082] Example 8

[0083] Preparation of Prepolymer

[0084] Add 0.8 g of sodium persulfate initiator, 1.5 g of AEO-3 emulsifier, and 300 mL of deionized water into a single-necked flask equipped with a magnetic stir bar in sequence, and then stir magnetically at room temperature for 20 min; separately weigh 8 g of ethyl acrylate and 44 g of methyl methacrylate monomers and mix them evenly, and then slowly add them dropwise to the above mixed solution at a rate of 5 mL / min under stirring conditions. After the addition is completed, heat and react at 80 °C for 1.5 h under nitrogen protection. Immediately transfer to an ice-water bath for sufficient cooling after the reaction is completed, and the prepolymer is obtained.

[0085] Preparation of Superhydrophilic Antifogging Coating

[0086] Add 5 g of sodium methallylsulfonate, 0.2 g of potassium persulfate, 33 mL of acetonitrile, and 6 mL of isopropanol into a single-necked flask equipped with a magnetic stir bar in sequence, and stir at room temperature until completely dissolved. Slowly add 22 mL of the prepolymer obtained in step (1) to the above solution at a dropping rate of 10 mL / min, and stir at room temperature until evenly dispersed after the addition is completed. React at 60 °C for 24 h under nitrogen protection, and immediately cool with an ice-water bath after the reaction is completed to obtain a superhydrophilic antifogging coating with superhydrophilic antifogging function.

[0087] Example 9

[0088] Preparation of Prepolymer

[0089] Add 1.0 g of sodium persulfate initiator, 1.0 g of Tween-80 emulsifier, and 250 mL of deionized water to a single-necked flask equipped with a magnetic stir bar in sequence, and then stir magnetically at room temperature for 15 min; separately weigh 25 g of methyl acrylate and 50 g of 2-hydroxyethyl methacrylate monomers and mix them evenly. Subsequently, slowly add the mixture dropwise to the above mixed solution at a rate of 6 mL / min under stirring conditions. After the addition is completed, heat and react at 80 °C for 2.5 h under nitrogen protection. Immediately transfer it to an ice-water bath for sufficient cooling after the reaction is completed to obtain the prepolymer.

[0090] Preparation of superhydrophilic anti-fog coating

[0091] Add 7 g of acryloyloxyethyl dimethylbenzyl ammonium chloride, 0.2 g of potassium persulfate, 40 mL of acetonitrile, and 8 mL of butyl acetate to a single-necked flask equipped with a magnetic stir bar in sequence, and stir at room temperature until completely dissolved. Slowly add 20 mL of the prepolymer obtained in step (1) to the above solution at a dropping rate of 8 mL / min. After the addition is completed, stir at room temperature until evenly dispersed. React at 65 °C for 21 h under nitrogen protection. Immediately cool it with an ice-water bath after the reaction is completed to obtain the superhydrophilic anti-fog coating with superhydrophilic anti-fog function.

[0092] Application Example 1

[0093] Preparation of superhydrophilic anti-fog coating

[0094] Take 6.0 g of the superhydrophilic anti-fog coating prepared in Example 1, slowly add it dropwise to 80 mL of deionized water under stirring conditions, and stir at room temperature for 2 h until evenly dispersed. Uniformly coat the diluted superhydrophilic anti-fog coating on the surface of the glass substrate by spin coating, and the coating amount of the emulsion is 0.1 - 10 g / m 2 , and then dry it at 60 °C to obtain the superhydrophilic anti-fog coating.

[0095] Application Example 2

[0096] Preparation of superhydrophilic anti-fog coating

[0097] Take 5.0 g of the superhydrophilic anti-fog coating prepared in Example 2, slowly add it dropwise to 75 mL of deionized water under stirring conditions, and stir at room temperature for 1.5 h until evenly dispersed. The stirring speed is 500 rpm. Uniformly coat the diluted coating solution on the surface of the glass substrate by spin coating, and the coating amount of the emulsion is 0.1 - 10 g / m 2 , and then dry it at 60 °C to obtain the superhydrophilic anti-fog coating.

[0098] Application Example 3

[0099] Preparation of superhydrophilic anti-fog coating

[0100] Take 6.0 g of the superhydrophilic anti-fog coating prepared in Example 3, and slowly add it dropwise to 40 mL of deionized water under stirring conditions. Stir for 2 h at room temperature until uniformly dispersed, with a stirring speed of 4000 rpm. The diluted coating solution is uniformly coated on the surface of the glass substrate by spin coating, and the coating amount of the emulsion is 0.1 - 10 g / m 2 , and then dried at 70 °C to obtain the superhydrophilic anti-fog coating.

[0101] Application Example 4

[0102] Preparation of Superhydrophilic Anti-Fog Coating

[0103] Take 6.0 g of the superhydrophilic anti-fog coating prepared in Example 4, and slowly add it dropwise to 100 mL of deionized water under stirring conditions. Stir for 1.5 h at room temperature until uniformly dispersed, with a stirring speed of 3500 rpm. The diluted coating solution is uniformly coated on the surface of the glass substrate by spin coating, and the coating amount of the emulsion is 0.1 - 10 g / m 2 , and then dried at 60 °C to obtain the superhydrophilic anti-fog coating.

[0104] Application Example 5

[0105] Preparation of Superhydrophilic Anti-Fog Coating

[0106] Take 6 g of the superhydrophilic anti-fog coating prepared in Example 5, and slowly add it dropwise to a mixed solvent of 80 mL of deionized water and 10 mL of ethanol under stirring conditions. Stir for 2 h at room temperature until uniformly dispersed, with a stirring speed of 2000 rpm. The diluted coating solution is uniformly coated on the surface of the glass substrate by spin coating, and the coating amount of the emulsion is 0.1 - 10 g / m 2 , and then dried at 60 °C to obtain the superhydrophilic anti-fog coating.

[0107] Application Example 6

[0108] Preparation of Superhydrophilic Anti-Fog Coating

[0109] Take 10 g of the superhydrophilic anti-fog coating prepared in Example 6, and slowly add it dropwise to a mixed solvent of 70 mL of deionized water and 5 mL of ethanol under stirring conditions. Stir for 2 h at room temperature until uniformly dispersed, with a stirring speed of 1000 rpm. The diluted coating solution is uniformly coated on the surface of the glass substrate by spin coating, and the coating amount of the emulsion is 0.1 - 10 g / m 2 , and then dried at 60 °C to obtain the superhydrophilic anti-fog coating.

[0110] Performance Characterization

[0111] 1. The superhydrophilic anti-fog coatings and blank glass slides prepared in Application Examples 1 to 6 were respectively taken and subjected to a hot fog test according to the requirements of GB / T 31726-2015. The superhydrophilic anti-fog coatings and blank glass slides prepared in this invention were respectively placed 20 s above the mouth of a beaker filled with hot water (80 °C) (the distance between the sample and the water surface was 3 cm). The physical photos of the hot fog test for Application Example 1 and the blank glass photo are shown as Figure 1 in a) and b), and the physical photos of the hot fog test for Application Examples 2 to 6 are shown as Figure 2 shown. It can be observed from the figures that the blank glass slide has no anti-fog effect, resulting in blurred vision, while there is no fogging phenomenon in the superhydrophilic anti-fog coatings prepared in the application examples of this invention, indicating that the superhydrophilic anti-fog coatings of this invention have excellent anti-fog performance.

[0112] Furthermore, the hydrophilicity of the coatings was verified by contact angle measurement. Figure 1 c) and d) in Figure 2 are respectively the contact angle measurement results of the blank glass slide and the superhydrophilic anti-fog coating prepared in Application Example 1 of this invention.

[0113] are respectively the contact angle measurement results corresponding to Application Examples 2 to 6. It can be seen that the contact angle of the blank glass slide is as high as 35°, while the contact angle of the superhydrophilic anti-fog coating prepared in Application Example 1 is only 7°. The contact angles of the superhydrophilic anti-fog coatings of Application Examples 2 to 6 are also 12°, 7°, 7°, 8°, and 8° respectively, showing good superhydrophilicity, further verifying that the superhydrophilic anti-fog coatings of this invention have excellent anti-fog performance.

[0113] 2. To test the effect of the superhydrophilic anti-fog coating of this invention on the visible light transmittance of the glass substrate, the blank glass slide and the superhydrophilic anti-fog coatings prepared in Application Examples 1 to 6 of this invention were respectively tested for their UV-vis spectra with air as the background (the results are shown as Figure 3 shown). It can be seen from the figure that the superhydrophilic anti-fog coating not only does not affect the light transmittance of the glass substrate, but also has a certain light transmittance enhancement effect on the glass substrate. This is mainly because the presence of the polymer coating reduces the refractive index difference between air and the glass substrate, thereby achieving the effect of reducing the reflection of incident light and increasing the transmittance at the same time.

[0114] Figure 4 is the physical photo of the glass slide with the superhydrophilic anti-fog coating prepared in Application Example 1 of this invention. It can be seen that the coating is uniform and completely transparent.

[0115] The above results indicate that the superhydrophilic anti-fog coating prepared in this invention solves the problem of low visible light transmittance and can meet the application requirements of transparent materials.

[0116] 3. The superhydrophilic anti-fog coating prepared in Application Example 1 of this invention was taken, and the adhesion of the anti-fog coating was tested by the cross-cut method specified in GB / T 9286-88. The results are asFigure 5 As shown in Figure 5 , it can be seen that after cutting with a cutting knife in the horizontal and vertical directions, the cutting edges are completely smooth and there is no shedding, indicating that the coating can reach the highest adhesion level of Grade 0.

[0117] 4. To verify the self-healing performance of the superhydrophilic anti-fog coating prepared by the present invention, the superhydrophilic anti-fog coating prepared by the present invention was damaged with a cutter to draw the word "UJN" (the physical diagram is as shown in Figure 6 b)), and then a hot fog experiment was carried out for 20 s (the physical diagram is as shown in Figure 6 c)), and finally the superhydrophilic anti-fog coating after the hot fog experiment was dried (the physical diagram is as shown in Figure 6 d)). It can be seen from the physical photos that after drying, the scratches on the superhydrophilic anti-fog coating have completely disappeared, indicating that the superhydrophilic anti-fog coating has excellent self-healing function. When the coating is damaged by external stress, it can be repaired through the self-healing function, thereby improving the service life of the coating.

[0118] 5. To further prove the erosion resistance and service life of the superhydrophilic anti-fog coating prepared by the application example of the present invention, a commercially available anti-fog coating and the anti-fog coating obtained in Example 1 were respectively coated on the surface of a glass sheet in the same coating method, and the obtained coated sheets were subjected to an erosion experiment. Figure 7 a) is a physical photo of the coating obtained by coating a commercially available anti-fog coating after 1 h of water flow erosion and then performing a hot fog experiment. Figure 7 b) is a physical photo of the coating obtained after coating the superhydrophilic anti-fog coating of Example 1, that is, the superhydrophilic anti-fog coating of Application Example 1, after 1 h of water flow erosion and then performing a hot fog experiment. It can be seen through observation that after water flow erosion, the commercially available anti-fog coating has completely lost its anti-fog effect, while the superhydrophilic anti-fog coating of Application Example 1 still shows excellent anti-fog effect. It shows that the superhydrophilic anti-fog coating prepared by the present invention can maintain the anti-fog performance for a long time in a humid environment or under rain immersion and other environments. Combining its self-healing function, its service life can be significantly improved.

[0119] In summary, the superhydrophilic anti-fog coating prepared by the superhydrophilic anti-fog coating provided by the present invention has excellent anti-fog performance, good superhydrophilicity, can improve the transmission effect, and also has a high self-healing function.

[0120] The above embodiments only exemplarily illustrate the principles and effects of the present invention, rather than limiting the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a superhydrophilic anti-fog coating, characterized in that, It includes the following steps: (1) Preparation of the prepolymer; (2) Preparation of the superhydrophilic antifogging coating; Specifically, it includes the following steps: (1) Preparation of the prepolymer: Mix the initiator and emulsifier, add Solvent I and stir. After stirring evenly, a mixed solution is obtained. Take the acrylic monomers and methacrylate monomers, mix them evenly, and then dropwise add them to the above mixed solution under stirring. After the dropping is completed, react under nitrogen protection. After the reaction is completed, perform cooling treatment to obtain the prepolymer; (2) Preparation of the superhydrophilic antifogging coating: Take the ionic monomer and initiator, add Solvent II, stir until dissolved, and then dropwise add the prepolymer obtained in step (1) to the solution. After the dropping is completed, stir evenly and perform a heating reaction under nitrogen protection. After the reaction is completed, perform cooling treatment to obtain the superhydrophilic antifogging coating; The initiators described in step (1) and step (2) are both selected from persulfate compounds; The emulsifier is selected from nonionic emulsifiers; The Solvent I is selected from one or more of water, acetonitrile, ethanol, butyl acetate, and ethyl acetate; The acrylic monomers are selected from one or more of acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, and n-butyl acrylate; The methacrylate monomers are selected from one or more of methacrylic acid, methyl methacrylate, and 2-hydroxyethyl methacrylate; In step (1), the dropping rate is 1-10 mL / min; In step (1), the mass ratio of the initiator to the emulsifier is (1-5):(5-10); In step (1), the mass ratio of the initiator to the total amount of acrylic monomers and methacrylate monomers is (1-8):(35-200); In step (1), the reaction temperature is 50-90 °C and the reaction time is 0.5-6 h; In step (1), the mass ratio of the total amount of acrylic monomers and methacrylate monomers to the solvent is (1-5):(5-100); In step (2), the ionic monomer is selected from one or more of methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl dimethyl benzyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, sodium methallyl sulfonate, and sodium p-styrene sulfonate; In step (2), the Solvent II is selected from one or more of water, acetonitrile, ethanol, isopropanol, and glycerol; In step (2), the mass ratio of the initiator to the ionic monomer is (1-9):(10-200); In step (2), the mass ratio of the ionic monomer to the prepolymer is (1-7):(1-120); In step (2), the mass ratio of the ionic monomer to the Solvent II is (1-5):(5-10); In step (2), the dropping rate of the prepolymer is 0.5-10 mL / min; In step (2), the reaction temperature is 50-90 °C and the reaction time is 3-24 h.

2. A superhydrophilic antifogging coating prepared by the method described in claim 1.

3. A superhydrophilic anti-fog coating, characterized in that, It includes the superhydrophilic antifogging coating described in claim 1.

4. A method for preparing the superhydrophilic anti-fog coating according to claim 3, characterized in that, It includes the following steps: Drop the superhydrophilic antifogging coating into the diluent, stir at room temperature until evenly dispersed, evenly coat the obtained emulsion on the surface of the glass substrate, and dry it to obtain the superhydrophilic antifogging coating; The mass ratio of the superhydrophilic anti-fog coating to the diluent is (1~5):(1~80); The diluent is selected from one or more of water, acetonitrile, ethanol, isopropanol, glycerol, and butyl acetate.

5. Application of the superhydrophilic anti-fog coating according to claim 3 in the fields of glasses, protective masks, windshield, and solar panels.

Images