Hydrophilic oleophobic coating as well as preparation method and application thereof

Abstract

The invention discloses a hydrophilic and oleophobic coating as well as a preparation method and application thereof, the method comprises the following steps: S1, mixing a perfluorosilane coupling agent with an isopropanol solution to obtain a first mixed solution; s2, adding an acid catalyst into the first mixed solution to obtain a first reaction solution; s3, mixing water, isopropanol, potassium silicate and potassium methylsilicate to obtain a second mixed solution; s4, adding perfluoroalkyl betaine into the second mixed solution to obtain a second reaction solution; s5, mixing the first reaction solution with the second reaction solution to obtain the hydrophilic and oleophobic coating. The hydrophilic and oleophobic coating prepared by the invention has super-strong hydrophilicity and oleophobicity, and the obtained coating material improves the oil stain cleaning capacity and cleaning efficiency.

Description

Technical Field

[0001] The present invention relates to the field of materials, and in particular to a hydrophilic oleophobic coating and a preparation method and application thereof. Background Art

[0002] Kitchen grease stains are relatively difficult to clean. Many people spend a lot of time cleaning kitchen grease stains. Currently, there are several types of easy-to-clean coatings used in the kitchen:

[0003] 1. Use materials with smooth surface, hard texture and good chemical stability such as glass and mirror stainless steel, so that users can use strong decontamination detergents, scouring pads and other strong decontamination agents to strongly remove stains during cleaning. This allows users to achieve the effect of reducing cleaning time. However, this will increase the cost of material use, and strong decontamination agents will pollute the environment and cause damage to human skin.

[0004] 2. Use double-repellent materials. Double-repellent materials refer to materials with low surface energy and contact angles greater than 90 degrees for both oil and water. This can greatly reduce the adhesion of stains, thereby reducing the cleaning time. However, the kitchen fumes are large, and the fumes that are oxidized and polymerized by heat will become sticky and more easily adhere to the surface of general double-repellent materials. This makes it more difficult to clean. At the same time, when wiping the surface with a wet rag, fog-like stains will be left due to the hydrophobicity of the material. It always gives people a psychological feeling that it is not wiped clean. Using dry and wet rags to wipe alternately increases the difficulty of cleaning the material.

[0005] 3. Hydrophilic and easy-to-clean paint. Hydrophilic and easy-to-clean paint has excellent easy-to-clean performance. Because the surface has excellent hydrophilicity, it can allow water molecules to quickly form a water film on the surface, thereby floating up the stains. However, hydrophilic paint generally also has good lipophilicity. If the oil stain has formed a water film on the surface, it will be difficult to form a water film. You need to spray water before cleaning, and then wait for a while before cleaning.

[0006] The oil stain cleaning materials in the prior art have poor cleaning ability for oil stains and low cleaning efficiency. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a hydrophilic and oleophobic coating that can improve the oil cleaning ability and cleaning efficiency.

[0008] In order to solve this problem, on the one hand, the present invention provides a method for preparing a hydrophilic oleophobic coating, the method comprising:

[0009] S1. mixing a perfluorosilane coupling agent with an isopropanol solution to obtain a first mixed solution;

[0010] S2. adding an acidic catalyst to the first mixed solution to obtain a first reaction solution;

[0011] S3. Mixing water, isopropanol, potassium silicate and potassium methyl silicate to obtain a second mixed solution;

[0012] S4. adding perfluoroalkyl betaine to the second mixed solution to obtain a second reaction solution;

[0013] S5. Mixing the first reaction solution and the second reaction solution to obtain a hydrophilic and oleophobic coating.

[0014] Furthermore, the mass ratio of the perfluorosilane coupling agent to the isopropanol solution is (1-3):(30-50); the mass ratio of the perfluorosilane coupling agent to the acid catalyst is (5-15):1.

[0015] Furthermore, the mass ratio of the water, the isopropanol, the potassium silicate and the potassium methyl silicate is (20-30): (10-20): (30-50): (0.5-3).

[0016] Furthermore, the mass ratio of the perfluorosilane coupling agent to the potassium silicate is 1:(150-300).

[0017] Further, step S4 includes:

[0018] S401. Adding the perfluoroalkyl betaine and the defoamer to the second mixed solution to obtain a white colloidal silica sol;

[0019] S402. Use an ultrasonic homogenizer to homogenize the silica sol to obtain the second reaction solution.

[0020] Furthermore, the mass ratio of the perfluoroalkyl betaine to the defoaming agent is (5-15):2.

[0021] Furthermore, the mass ratio of the potassium methyl silicate to the defoaming agent is (5-30):2.

[0022] Furthermore, in step S5, the mass ratio of the first reaction solution to the second reaction solution is 2:(70-90).

[0023] Furthermore, the solid content of the potassium silicate is 25%-35%, and the modulus is 3.0-3.5.

[0024] Further, step S5 includes:

[0025] S501. adding the second reaction solution to the reaction vessel, and stirring the second reaction solution;

[0026] S502. Slowly add the first reaction solution to the second reaction solution under continuous stirring to generate a hydrophilic and oleophobic coating.

[0027] Further, step S2 includes:

[0028] S201. adding the acidic catalyst to the first mixed solution to obtain a white colloidal silane polymer;

[0029] S202. Use an ultrasonic homogenizer to homogenize the silane polymer to obtain the first reaction solution; wherein the ratio of the volume of the silane polymer to the power of the ultrasonic homogenizer is (8:45) mL / W.

[0030] Furthermore, after step S2, the following steps are further included:

[0031] The first reaction solution is stored at 1°C-5°C for later use.

[0032] Furthermore, the defoaming agent is at least one of diisobutyl carbinol, diethyl hexanol, isooctyl alcohol and isoamyl alcohol.

[0033] Furthermore, the perfluorosilane coupling agent is at least one of tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane and heptadecafluorodecyltriethoxysilane.

[0034] Furthermore, the acidic catalyst is at least one of acetic acid, gallic acid and citric acid.

[0035] On the other hand, the present invention provides a hydrophilic oleophobic coating, which is prepared by the method as described above.

[0036] On the other hand, the present invention provides an application of a hydrophilic oleophobic coating, wherein the hydrophilic oleophobic coating is used to form a coating on the surface of a substrate, and the hydrophilic oleophobic coating is prepared by the method as described above.

[0037] The present invention has the following beneficial effects:

[0038] The present invention mixes a perfluorosilane coupling agent with an isopropanol solution to obtain a first mixed solution; an acidic catalyst is added to the first mixed solution to obtain a first reaction solution; water, isopropanol, potassium silicate, and potassium methyl silicate are mixed to obtain a second mixed solution; perfluoroalkyl betaine is added to the second mixed solution to obtain a second reaction solution; the first reaction solution is mixed with the second reaction solution to obtain a silane oligomer; and the hydrophilic oleophobic coating is used as a hydrophilic oleophobic coating. The present invention uses a perfluorosilane coupling agent to prepare a silane hydrolyzate using acetic acid as a catalyst to generate a perfluorosilanol with a silanol, and the alcohol hydroxyl group has a high activity, which will further generate a silane polymer. When a white colloid is found, it is a silane polymer produced by excessive cross-linking of the silane polymer. The over-crosslinked silane polymer can be broken up using an ultrasonic homogenizer to make it a soluble silane oligomer. It is relatively stable in an isopropanol solution system. It can be stored for a long time at low temperatures. Potassium silicate is also more likely to be hydrolyzed in an isopropanol-water mixed solution system to form a silica sol. Ultrasonic homogenization can play the same role. The silica sol formed by potassium silicate and the silane oligomer formed by the perfluorosilane coupling agent are partially polymerized. Ultrasonic homogenization can also control the molecular weight and degree of polymerization to form new silane oligomers. However, the perfluoro group is completely hydrophobic, so the water solubility is relatively poor, and an emulsion will be formed. However, the silane oligomers formed during the curing process of the coating can be well cross-linked. Perfluoroalkyl betaine, as a zwitterionic surfactant, is dissolved in a water-alcohol mixed solution, which can greatly reduce the viscosity of the coating, increase the leveling wettability of the material, and act as a dispersant to improve the problem of poor solubility. At the same time, the perfluoroalkyl betaine has a perfluoro group in its molecular structure, and a hydrophilic carboxyl group, which itself also has a certain hydrophilic and oleophobic property. The influence of the introduction of other groups on the surface hydrophilic and oleophobic properties of the material is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 is a flow chart of a method for preparing a hydrophilic oleophobic coating provided by an embodiment of the present invention;

[0041] Figure 2 It is a scanning electron microscope image of a hydrophilic oleophobic coating provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0043] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0044] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0045] Example 1

[0046] like Figure 1 As shown, an embodiment of the present invention provides a method for preparing a hydrophilic oleophobic coating, the method comprising:

[0047] S1. mixing a perfluorosilane coupling agent with an isopropanol solution to obtain a first mixed solution;

[0048] S2. adding an acidic catalyst to the first mixed solution to obtain a first reaction solution;

[0049] S3. Mixing water, isopropanol, potassium silicate and potassium methyl silicate to obtain a second mixed solution;

[0050] S4. adding perfluoroalkyl betaine to the second mixed solution to obtain a second reaction solution;

[0051] S5. Mixing the first reaction solution and the second reaction solution to obtain a hydrophilic-oleophobic coating.

[0052] Exemplarily, the mass ratio of the perfluorosilane coupling agent to the isopropanol solution is (1-3):(30-50); the mass ratio of the perfluorosilane coupling agent to the acid catalyst is (5-15):1.

[0053] In the examples of this specification, a perfluorosilane coupling agent is used to prepare a silane hydrolyzate with acetic acid as a catalyst to generate perfluorosilanol with silanol. The alcoholic hydroxyl group has a high activity and will further generate a silane polymer. When a white colloid is found, it is a silane polymer produced by excessive cross-linking of the silane polymer. An ultrasonic homogenizer can be used to break up the excessively cross-linked silane polymer to make it a soluble silane oligomer. It is relatively stable in an isopropanol solution system and can be stored for a long time at low temperatures.

[0054] In the examples of this specification, the mass ratio of the water, the isopropyl alcohol, the potassium silicate, and the potassium methyl silicate is (20-30): (10-20): (30-50): (0.5-3).

[0055] In the embodiments of this specification, potassium silicate is also easy to hydrolyze in an isopropanol-water mixed solution system to form silica sol. Potassium silicate has certain film-forming properties as a main resin agent, and potassium methyl silicate can help increase the hydrolysis resistance, reduce the hydrolysis performance of the coating after drying, and increase the service life of the material. At the same time, it contains potassium ions, which can play an excellent hydrophilic role. The hydrolyzed silica sol can also fix perfluorosilane oligomers well.

[0056] In the examples of this specification, the mass ratio of the perfluorosilane coupling agent to the potassium silicate is 1:(150-300).

[0057] In the embodiments of this specification, K+ has a strong hydrophilic effect, and the perfluoro group also has a hydrophobic and oleophobic function. The ratio of the K+ content to the perfluoro group content should be controlled. If the potassium ion content is too high, the oleophobicity will be insufficient, and if the perfluoro group is too much, the material will be insufficiently hydrophilic. The mass ratio of the perfluorosilane coupling agent to the above potassium silicate is set to 1: (150-300), which can ensure the hydrophilicity and oleophobicity of the material at the same time.

[0058] Exemplarily, the mass ratio of the perfluoroalkyl betaine to the defoamer is (5-15): 2. The mass ratio of the potassium methyl silicate to the defoamer is (5-30): 2.

[0059] In the embodiments of this specification, perfluoroalkyl betaine is dissolved in a water-alcohol mixed solution as a zwitterionic surfactant, which can significantly reduce the viscosity of the coating, increase the leveling wettability of the material, and act as a dispersant to improve the problem of poor solubility. At the same time, perfluoroalkyl betaine has a perfluoro group in its molecular structure, and a hydrophilic carboxyl group, which itself also has a certain hydrophilic and oleophobic property, which can reduce the influence of the introduction of other groups on the hydrophilic and oleophobic properties of the material surface.

[0060] In the embodiment of this specification, step S2 includes:

[0061] S201. Adding the acidic catalyst to the first mixed solution to obtain a white colloidal silane polymer;

[0062] S202. Use an ultrasonic homogenizer to homogenize the above-mentioned silane polymer to obtain the above-mentioned first reaction solution; wherein, the ratio of the volume of the above-mentioned silane polymer to the power of the above-mentioned ultrasonic homogenizer is (8:45) mL / W.

[0063] In the embodiments of the present specification, the ultrasonic homogenizer can promote the hydrolysis of potassium silicate in the isopropanol-water mixed solution system to form silica sol, thereby improving the preparation efficiency of the first reaction solution.

[0064] In the embodiment of this specification, after step S2, the following steps are also included:

[0065] The first reaction solution is stored at 1°C-5°C for later use.

[0066] Exemplarily, 0.5-1.5 parts of perfluorosilane coupling agent can be slowly added dropwise to 15-25 parts of isopropanol solution and stirred at a speed of 500r / min. After the addition is completed, 0.1 parts of acidic catalyst are added and stirred continuously until a small amount of white colloidal substance is produced. Then a probe ultrasonic homogenizer (80ml using a power of 450W) is used for homogenization to break up the white colloidal substance until a transparent solution is formed. Place in a 5°C incubator for standby use to obtain a first reaction solution.

[0067] In the embodiment of this specification, the solid content of the potassium silicate in step S3 is 25%-35%, and the modulus is 3.0-3.5.

[0068] In the embodiment of this specification, step S4 includes:

[0069] S401. Adding the perfluoroalkyl betaine and the defoaming agent to the second mixed solution to obtain a white colloidal silica sol;

[0070] S402. Use an ultrasonic homogenizer to homogenize the silica sol to obtain the second reaction solution.

[0071] For example, 20-30 parts of water, 10-20 parts of isopropanol, 30-50 parts of potassium silicate, and 0.5-3 parts of potassium methyl silicate can be fully stirred and mixed, and 0.5-1.5 parts of perfluoroalkyl betaine (C8F17SO2NHCH2CH2CH2N+(CH3)2CH2COO-) and 0.2 parts of diisobutyl carbinol (defoaming agent) can be added and stirred and mixed. After mixing, a probe ultrasonic homogenizer (80 ml with a power of 450 W) is used for homogenization to completely break up the formed white colloid to prepare the second reaction solution.

[0072] Exemplarily, step S5 includes:

[0073] S501. Adding the second reaction solution to the reaction vessel, and stirring the second reaction solution;

[0074] S502. Slowly drop the first reaction solution into the second reaction solution under continuous stirring to generate a hydrophilic oleophobic coating, wherein the hydrophilic oleophobic coating is a translucent silane oligomer solution.

[0075] In the embodiments of this specification, the hydrophilic oleophobic coating has both strong hydrophilicity and oleophobicity, so when it is used as a coating to form a coating, the small oil attached to the surface can be arranged into small uneven oil droplets, so that when cleaning, the material will greatly reduce the problem of oil film coverage of general hydrophilic materials, thereby improving the wetting ability of water on the material surface and quickly strengthening the wetting ability of the material. Improve the ability to be easy to clean, and at the same time, when using a wet rag to wipe the material, the problem of mist-like liquid beads caused by the double-phobic material will not occur.

[0076] In the embodiment of the present specification, the mass ratio of the first reaction solution to the second reaction solution in step S5 is 2:(70-90).

[0077] For example, 2 parts of the first reaction solution can be slowly added dropwise to 70-90 parts of the second reaction solution with stirring during the whole process. After the addition, a probe ultrasonic homogenizer (80 ml using 450 W power) is used to completely break up the formed white colloid to form a translucent solution to obtain a hydrophilic and oleophobic coating.

[0078] In the embodiment of this specification, the silica sol formed by potassium silicate and the silane oligomer formed by the perfluorosilane coupling agent are partially polymerized, and ultrasonic homogenization can also play a role in controlling the molecular weight and degree of polymerization to form new silane oligomers. However, since the perfluoro group is completely hydrophobic, the water solubility is relatively poor and an emulsion will be formed; but the silane oligomer formed during the curing process of the coating can be well cross-linked.

[0079] Exemplarily, the perfluorosilane coupling agent is at least one of tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane and heptadecafluorodecyltriethoxysilane.

[0080] Exemplarily, the acidic catalyst is at least one of acetic acid, gallic acid, and citric acid.

[0081] In the embodiments of the present specification, the defoaming agent is at least one of diisobutyl carbinol, diethyl hexanol, isooctyl alcohol and isoamyl alcohol.

[0082] In the embodiments of this specification, the hydrophilic and oleophobic coating is an unconventional wetting coating. Because it has both strong hydrophilicity and oleophobicity, the small oil attached to the surface can be arranged into small uneven oil droplets. In this way, the material will greatly reduce the problem of oil film coverage of general hydrophilic materials during cleaning, thereby improving the wetting ability of water on the material surface and quickly strengthening the wetting ability of the material. The easy cleaning ability is improved, and at the same time, when using a wet cloth to wipe the material, the problem of mist-like liquid beads caused by the double-phobic material will not occur.

[0083] Example 2

[0084] This embodiment discloses a method for preparing a hydrophilic oleophobic coating, comprising the following steps:

[0085] Step 1: Slowly drop 0.5 parts of tridecafluorooctyl triethoxysilane into 15 parts of isopropanol solution and stir at a speed of 500r / min. After the addition is completed, add 0.1 parts of acetic acid and continue stirring until a small amount of white colloidal substance is produced. Use a probe ultrasonic homogenizer (80ml using 450W power) to break up the white colloidal substance until a transparent solution is formed, and place it in a 5°C incubator for standby use to obtain the first reaction solution.

[0086] Step 2: 20 parts of water, 10 parts of isopropanol, 30 parts of potassium silicate (35% solid content, modulus 3.5), 0.5 parts of potassium methyl silicate were fully stirred and mixed, and 0.5 parts of perfluoroalkyl betaine (C8F17SO2NHCH2CH2CH2N+(CH3)2CH2COO-) and 0.2 parts of diisobutyl carbinol (defoaming agent) were fully stirred and mixed. After mixing, a probe ultrasonic homogenizer (80 ml with 450W power) was used to completely break up the formed white colloid to prepare the second reaction solution.

[0087] Step 3: Take 2 parts of the first reaction solution and slowly add them dropwise to 70 parts of the second reaction solution, stirring the whole process to form a white colloid. After the addition, use a probe ultrasonic homogenizer (80 ml with 450W power) to completely break up the formed white colloid to form a translucent solution to obtain a hydrophilic and oleophobic coating.

[0088] Example 3

[0089] This embodiment discloses a method for preparing a hydrophilic oleophobic coating, comprising the following steps:

[0090] Step 1: Slowly drop 1 part of heptadecafluorodecyltrimethoxysilane into 20 parts of isopropanol solution and stir at 500r / min. After the addition is complete, add 0.2 parts of gallic acid and continue stirring until a small amount of white colloid is produced. Use a probe ultrasonic homogenizer (80ml using 450W power) to break up the white colloid until a transparent solution is formed, and place it in a 5°C incubator for standby use to obtain the first reaction solution.

[0091] Step 2: 25 parts of water, 15 parts of isopropanol, 40 parts of potassium silicate (35% solid content, modulus 3.5), and 2 parts of potassium methyl silicate are fully stirred and mixed, and 1 part of perfluoroalkyl betaine (C8F17SO2NHCH2CH2CH2N+(CH3)2CH2COO-) and 0.2 parts of diisobutyl carbinol (defoaming agent) are added and fully stirred and mixed. After mixing, a probe ultrasonic homogenizer (80 ml using 450W power) is used to completely break up the formed white colloid to prepare the second reaction solution.

[0092] Step 3: Take 2 parts of the first reaction solution and slowly add them dropwise to 80 parts of the second reaction solution, stirring the whole process to form a white colloid. After the addition, use a probe ultrasonic homogenizer (80 ml with 450 W power) to completely break up the formed white colloid to form a translucent solution to obtain a hydrophilic and oleophobic coating.

[0093] Example 4

[0094] This embodiment discloses a method for preparing a hydrophilic oleophobic coating, comprising the following steps:

[0095] Step 1: Slowly drop 1.5 parts of heptadecafluorodecyltriethoxysilane into 25 parts of isopropanol solution and stir at 500r / min. After the addition is complete, add 0.1 parts of citric acid and continue stirring until a small amount of white colloid is produced. Use a probe ultrasonic homogenizer (80ml using 450W power) to break up the white colloid until a transparent solution is formed, and place it in a 5°C incubator for standby use to obtain the first reaction solution.

[0096] Step 2: 30 parts of water, 20 parts of isopropanol, 50 parts of potassium silicate (35% solid content, modulus 3.5), 3 parts of potassium methyl silicate were fully stirred and mixed, and 1.5 parts of perfluoroalkyl betaine (C8F17SO2NHCH2CH2CH2N+(CH3)2CH2COO-) and 0.2 parts of diisobutyl carbinol (defoaming agent) were added and stirred and mixed. After mixing, a probe ultrasonic homogenizer (80 ml with 450W power) was used to completely break up the formed white colloid to prepare the second reaction solution.

[0097] Step 3: Take 2 parts of the first reaction solution and slowly add them dropwise to 90 parts of the second reaction solution, stirring the whole process to form a white colloid. After the addition, use a probe ultrasonic homogenizer (80 ml with 450W power) to completely break up the formed white colloid to form a translucent solution to obtain a hydrophilic and oleophobic coating.

[0098] Example 5

[0099] This embodiment also discloses a hydrophilic oleophobic coating, which is obtained by the preparation method of embodiments 1-4. The hydrophilic oleophobic coating obtained in this embodiment is composed of spherical particles less than or equal to 30 nanometers. Figure 2 As shown, Figure 2 This is a scanning electron microscope image of a hydrophilic and oleophobic coating provided by an embodiment of the present invention. The image was imaged using a scanning electron microscope at 300,000 times. It can be seen that after cross-linking of silicate and fluorinated silane coupling agent, a large number of hydrophilic and oleophobic coatings with spherical particles less than 30 nanometers are formed. The coating is dense and uniform and has good bonding strength on the material surface, which proves that large-scale uncontrollable polymerization reactions do not occur during the material drying process. In the final coating, the smaller the material particles, the better the material properties will be in terms of density, toughness, and bonding strength.

[0100] The hydrophilic and oleophobic coating prepared in this embodiment is a silane oligomer. Optionally, the structural formula of the silane oligomer is as follows, wherein m and n are 2-5, and R can be KOH or the like.

[0101]

[0102] This embodiment also discloses an application of a hydrophilic oleophobic coating, wherein the hydrophilic oleophobic coating is used to form a coating on the surface of a substrate, and the hydrophilic oleophobic coating is obtained by the preparation method of embodiments 1 to 4. The substrate may be a metal plate, and the metal plate may include but is not limited to a galvanized plate.

[0103] The hydrophilic oleophobic coatings obtained in Examples 2-4 and the materials obtained in the comparative example were respectively applied to the surface of the galvanized sheet, and then dried at 165° C. for 30 minutes to form a coating, and the water contact angle and oil contact angle of the coating were tested. The test results are shown in Table 1 below:

[0104] Table 1

[0105] Water contact angle Oil contact angle hardness Binding force Example 2 18° 92° 7H Level 1 Example 3 22° 97° 7H Level 1 Example 4 24° 108° 7H Level 1

[0106] In summary, the hydrophilic and oleophobic coating prepared in this embodiment has moderate hardness and strong bonding force with the substrate; it also has super strong hydrophilicity and oleophobicity, so the small oil attached to the surface of the coating can be arranged into small uneven oil droplets, so that when cleaning, the material will greatly reduce the problem of oil film coverage of general hydrophilic materials, thereby improving the wetting ability of water on the surface of the material and quickly strengthening the wetting ability of the material. The easy-to-clean ability of the coating is improved, and at the same time, when using a wet rag to wipe the coating material, the problem of misty liquid beads caused by the double-phobic material will not be caused.

[0107] The above disclosures are only several preferred embodiments of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for preparing a hydrophilic oleophobic coating, characterized in that: The method comprises: S1. mixing a perfluorosilane coupling agent with an isopropanol solution to obtain a first mixed solution; S2. adding an acidic catalyst to the first mixed solution to obtain a first reaction solution; S3. Mixing water, isopropanol, potassium silicate and potassium methyl silicate to obtain a second mixed solution; S4. adding perfluoroalkyl betaine to the second mixed solution to obtain a second reaction solution; S5. Mixing the first reaction solution and the second reaction solution to obtain a hydrophilic and oleophobic coating.

2. The method according to claim 1, characterized in that The mass ratio of the perfluorosilane coupling agent to the isopropanol solution is (1-3):(30-50); the mass ratio of the perfluorosilane coupling agent to the acid catalyst is (5-15):

1.

3. The method according to claim 1, characterized in that The mass ratio of the water, the isopropanol, the potassium silicate and the potassium methyl silicate is (20-30):(10-20):(30-50):(0.5-3).

4. The method according to claim 3, characterized in that The mass ratio of the perfluorosilane coupling agent to the potassium silicate is 1:(150-300).

5. The method according to any one of claims 1 to 4, characterized in that: Step S4 includes: S401. Adding the perfluoroalkyl betaine and the defoamer to the second mixed solution to obtain a white colloidal silica sol; S402. Use an ultrasonic homogenizer to homogenize the silica sol to obtain the second reaction solution.

6. The method according to claim 5, wherein the mass ratio of the perfluoroalkyl betaine to the defoaming agent is (5-15):

2.

7. The method according to claim 5, characterized in that The mass ratio of the potassium methyl silicate to the defoaming agent is (5-30):

2.

8. The method according to any one of claims 1 to 4, characterized in that: In step S5, the mass ratio of the first reaction solution to the second reaction solution is 2:(70-90).

9. The method according to any one of claims 1 to 4, characterized in that: The solid content of the potassium silicate is 25%-35%, and the modulus is 3.0-3.

5.

10. The method according to any one of claims 1 to 4, characterized in that: Step S5 includes: S501. adding the second reaction solution to the reaction vessel, and stirring the second reaction solution; S502. Slowly add the first reaction solution to the second reaction solution under continuous stirring to generate a hydrophilic and oleophobic coating.

11. The method according to any one of claims 1 to 4, characterized in that: Step S2 includes: S201. adding the acidic catalyst to the first mixed solution to obtain a white colloidal silane polymer; S202. Use an ultrasonic homogenizer to homogenize the silane polymer to obtain the first reaction solution; wherein the ratio of the volume of the silane polymer to the power of the ultrasonic homogenizer is (8:45) mL / W.

12. The method according to any one of claims 1 to 4, characterized in that: After step S2, the following steps are also included: The first reaction solution is stored at 1°C-5°C for later use.

13. The method according to claim 5, characterized in that The defoaming agent is at least one of diisobutyl carbinol, diethyl hexanol, isooctyl alcohol and isoamyl alcohol.

14. The method according to any one of claims 1 to 4, characterized in that: The perfluorosilane coupling agent is at least one of tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane and heptadecafluorodecyltriethoxysilane.

15. The method according to any one of claims 1 to 4, characterized in that: The acidic catalyst is at least one of acetic acid, gallic acid and citric acid.

16. A hydrophilic oleophobic coating, characterized in that: The hydrophilic and oleophobic coating is prepared by the method described in any one of claims 1 to 15.

17. An application of a hydrophilic oleophobic coating, characterized in that: The hydrophilic oleophobic coating is used to form a coating on the surface of a substrate, and the hydrophilic oleophobic coating is prepared by the method described in any one of claims 1-15.

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