A hydrophobic, oleophobic, abrasion-resistant fluorine-containing functional coating and a method for producing the same

Abstract

The application provides a hydrophobic, oleophobic and wear-resistant fluorine-containing functional coating and a preparation method thereof. The hydrophobic, oleophobic and wear-resistant fluorine-containing functional coating comprises modified paste and fluorine-containing paint, and the mass ratio of the modified paste to the fluorine-containing paint is 2:5-8. The modified paste comprises fumed silica and oil-in-water emulsion, and the mass ratio of the fumed silica to the oil-in-water emulsion is 0.8-19:200. The oil-in-water emulsion comprises the following components in parts by weight: hydrogen-containing silicone oil 3.8-5.6 wt%, non-ionic surfactant 0.38-0.45 wt%, and the balance is deionized water. The coating prepared by the application has the performance that the hydrophobic angle is not less than 120°, the oleophobic angle is not less than 110°, and the wear resistance is greater than or equal to 6500.

Description

Technical Field

[0001] This invention belongs to the field of non-stick coating technology, specifically relating to a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating and its preparation method. Background Technology

[0002] In the industrial sector, carbon emissions are primarily influenced by the rate of resource consumption, making the extension of product lifespan crucial for reducing carbon emissions. Take non-stick baking appliances as an example; Teflon coatings are widely used, and since the coating always fails before the substrate, coating lifespan is a major concern.

[0003] Young's equation and Wenzel model have pointed the way for constructing superhydrophobic surfaces. Currently, the methods for preparing water-oil bihydrophobic surfaces can be roughly divided into two types: one is to construct rough micron and / or nanostructures on the material surface, and the construction methods include chemical etching, template method, composite coating method, electrochemical deposition method, etc.; the other is to modify the rough structure surface with low surface energy materials, such as fluorinated alkyl silanes, fluoropolymers, long-chain silanes, carboxylic acids and thiols, etc.; the two can also be combined to construct bihydrophobic surfaces.

[0004] Currently used fluorinated coatings generally have certain hydrophobicity and wear resistance, but there are few reports of dual oil and water repellency and wear resistance. Furthermore, existing superhydrophobic materials still have a series of application problems, such as harsh preparation conditions, expensive equipment and complex processes, and poor dispersibility of hydrophobic particles in water-based coatings. These problems restrict the promotion and application of such technologies, and thus fail to achieve the goal of extending the lifespan of industrial products and reducing carbon emissions.

[0005] Based on this, the problem to be solved in this case is: to develop a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating and its preparation method that is suitable for the large-scale production of baking utensils. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating and its preparation method. The coating of this invention uses a paste-like substance obtained from an oil-in-water microstructure emulsion and fumed silica as a modifying raw material for fluorinated paint. After mixing with the fluorinated paint, the hydrophobic particles are uniformly dispersed in the paint by mechanical stirring. Finally, after spraying and curing, the prepared coating meets the following performance requirements: a hydrophobic angle of not less than 120°, an oleophobic angle of not less than 110°, and a wear resistance of ≥6500 cycles.

[0007] To achieve the above technical objectives, the technical solution adopted in the embodiments of the present invention is as follows:

[0008] In a first aspect, embodiments of the present invention provide a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating, wherein the coating comprises a modified paste and a fluorinated paint, and the mass ratio of the modified paste to the fluorinated paint is 2:5 to 8.

[0009] The modified paste comprises fumed silica and an oil-in-water emulsion, wherein the mass ratio of fumed silica to oil-in-water emulsion is 0.8–19:200, and the oil-in-water emulsion comprises the following components in parts by weight: 3.8–5.6 wt% hydrogen-containing silicone oil, 0.38–0.45 wt% nonionic surfactant, and the balance being deionized water.

[0010] Furthermore, the fluorinated paint comprises polytetrafluoroethylene, 2,6,8-trimethyl-4-nonoxyethylene oxyethanol, 2,6-dimethyl-4-heptanone, 5-chloro-2-methyl-1-isothiazolin-3-one, 2-methyl-1-isothiazolin-3-one, and water.

[0011] Furthermore, the particle size of the fumed silica is 10–100 nm; the HLB value of the nonionic surfactant is 15.0–15.6; and the conductivity of the deionized water is ≤0.1 μS / cm.

[0012] Secondly, embodiments of the present invention provide a method for preparing the hydrophobic, oleophobic, and wear-resistant fluorinated functional coating described in the first aspect, comprising the following steps:

[0013] Step S1: Mechanically stir the modified paste and fluorine-containing paint to disperse them evenly at a stirring speed of 1800-3200 rpm;

[0014] Step S2: After stirring, the paint obtained is defoamed, filtered and large particulate impurities are removed to obtain modified paint. The modified paint is then atomized and sprayed onto the designated surface of the part.

[0015] Step S3: Perform high-temperature curing and sintering treatment on the sprayed parts to obtain a coating with a hydrophobic angle ≥120°, an oleophobic angle ≥110°, and a wear resistance cycle ≥6500.

[0016] Furthermore, the preparation method of the modified paste in step S1 includes the following steps:

[0017] (1) Hydrogen-containing silicone oil, nonionic surfactant, and deionized water are mixed and stirred at a high speed of 4600-5200 rpm to obtain an oil-in-water microemulsion.

[0018] (2) The obtained oil-in-water microemulsion was added to fumed silica and stirred at a high speed of 4600-5200 rpm to obtain a modified fumed silica slurry.

[0019] (3) After centrifuging the obtained modified fumed silica slurry, the supernatant is removed and some water is removed to make a modified paste. The viscosity of the modified paste is 100-500 mPa·s.

[0020] Furthermore, in step S2, the paint is atomized and sprayed onto the surface of a metal part with a hardness of 40 to 135 HB, and the spraying pressure during atomization is 0.2 to 0.4 MPa.

[0021] Furthermore, the process parameters for the high-temperature curing and sintering treatment described in step S3 are as follows: room temperature furnace entry, heating rate <40℃ / min, final curing temperature 360~420℃, holding time to film thickness ratio 0.5~1min / μm, and heat sources and insulation components distributed as needed in the furnace to control temperature fluctuations in each zone ≤±5℃.

[0022] Furthermore, in steps S1-S3, the amount of dust falling into the paint space is controlled, with the hourly dust amount ≤10mg / m³. 2 • h, the concentration of suspended particles with a diameter greater than 5 μm is ≤29 particles / m³ 3 .

[0023] The beneficial effects of the technical solution provided by the embodiments of the present invention are as follows:

[0024] The raw materials for preparing the superhydrophobic and wear-resistant fluorinated functional coating provided by this invention include a modified paste. The modified paste can be stored stably for a long time under simple sealed conditions, which is convenient for logistics and use. This invention optimizes the proportion of raw materials in the modified paste, so that each raw material can play its full role, and further improves the hydrophobicity and wear resistance of the fluorinated functional coating.

[0025] The modified slurry provided by this invention has a microstructure in which modified silica is uniformly dispersed in an oil-in-water emulsion. The modified silica is fumed silica with the oil-in-water emulsion adsorbed on its surface. This paste-like modified raw material solves the problems of agglomeration, sedimentation and dust pollution of powdered modified raw materials during the addition of them to paint. It not only has good water solubility, but is also easy to disperse evenly in paint, which is beneficial to improving film quality.

[0026] The oil-in-water emulsion provided by this invention, by mixing hydrogen-containing silicone oil, nonionic surfactant and deionized water and then performing high-speed shearing emulsification, can obtain a "microemulsion" with low viscosity, relatively uniform particle size and stable positive and negative charge centers, which is beneficial for uniformly encapsulating micro and nano silica particles and dispersing them in the paint system.

[0027] In the modified paste of this invention, silica is mainly a component for constructing the micro-protrusion structure of the final coating surface. Except for silica produced by the ester hydrolysis method, which has a hydrophobic surface, silica produced by the gas phase method and the precipitation method has a hydrophilic surface. Hydrophilicity easily causes nano-SiO2 to agglomerate into amorphous white powder in the paint system, resulting in poor dispersion. Moreover, it limits the amount of SiO2 added to a very low level, so that the nano-effect of SiO2 cannot be fully realized. Therefore, it is necessary to modify the SiO2 powder to be hydrophobic. According to the principle of composite, using hydrophobic materials to construct the micro-protrusion structure can also increase the hydrophobic effect to a certain extent.

[0028] Utilizing the numerous highly reactive and efficient Si-H bonds present on the surface of hydrogen-containing silicone oil as the main reactive groups with fumed silica, in a weakly alkaline environment, the highly reactive Si-H bonds are broken, and the active hydrogen atoms are replaced by hydroxyl groups, thus allowing the grafting of silanol groups. Then, the silanol groups on the SiO2 surface undergo a condensation reaction with -OH groups. After the reaction is complete, hydrophobic -CH3 groups are grafted, ultimately achieving the replacement of the hydrophilic hydroxyl groups with hydrophobic -CH3 groups in the nano-SiO2 microporous thermal insulation material.

[0029] The strong polar fluorine element contained in the fluorine-containing paint forms strong hydrogen bonds, which graft with the uniformly dispersed microemulsion containing silica particles, resulting in a denser structure and uniform distribution in the paint. This creates a uniformly distributed micro-convex texture after the paint film dries and cures, improving hydrophobicity and abrasion resistance.

[0030] The coating of this invention uses a paste-like substance made from an oil-in-water microstructure emulsion and fumed silica as a modifying raw material for fluorinated paint. After mixing with the fluorinated paint, the hydrophobic particles are uniformly dispersed in the paint by mechanical stirring. Finally, the coating is sprayed and cured. This method is not only convenient to operate and has good dispersibility, but also produces a coating with performance that meets the requirements of a hydrophobic angle of not less than 120°, an oleophobic angle of not less than 110°, and an abrasion resistance of ≥6500 cycles. Attached Figure Description

[0031] Figure 1 This is a process flow diagram of the preparation of fluorine-containing functional coatings in an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the microstructure of oil-in-water emulsion in an embodiment of the present invention.

[0033] Figure 3 This is a schematic diagram of the microstructure of modified silica in an embodiment of the present invention.

[0034] Figure 4 This is a schematic diagram illustrating the principle of fumed silica modification in an embodiment of the present invention.

[0035] Figure 5 These are scanning electron microscope images and trace component EDT detections of the unmodified coating in Comparative Example 5 of this invention.

[0036] Figure 6 yes Figure 5 EDT test results for region 1.

[0037] Figure 7 yes Figure 5 EDT test results for region 2 in the middle.

[0038] Figure 8 The coating after modification treatment in Example 3 of this invention was analyzed by scanning electron microscopy and trace component EDT.

[0039] Figure 9 yes Figure 8 EDT test results for region 1.

[0040] Figure 10 yes Figure 8 EDT test results for region 2 in the middle.

[0041] Figure 11 The SiO2 distribution of the modified coating in Example 3 of this invention was observed using a scanning electron microscope.

[0042] Figure 12 These are scanning electron microscope images of the poorly modified sample in Comparative Example 4, showing agglomeration and cracking.

[0043] Figure 13 This is the three-dimensional morphology of the coating surface that was successfully modified and did not agglomerate in Example 5.

[0044] Figure 14 These are comparison images of samples before and after the coating adhesion test in Example 5. (a) shows the sample before tape pull-out, and (b) shows the sample after tape pull-out.

[0045] Figure 15 This is a photograph of the coating after friction testing in Comparative Example 1 of this invention, showing the appearance of the coating after the substrate is exposed.

[0046] Figure 16 These are photographs of the hydrophobic and oleophobic tests of the coating in Comparative Example 5. 16a represents the hydrophobic test, and 16b represents the oleophobic test.

[0047] Figure 17 These are photographs of the hydrophobic and oleophobic coating tests in Example 5. 17a represents the hydrophobic test, and 17b represents the oleophobic test.

[0048] Explanation of reference numerals in the attached figures: 1-Deionized water; 2-Hydrogen-containing silicone oil; 3-Nonionic surfactant; 4-Fused silica; 5-Oil-in-water emulsion droplets. Detailed Implementation

[0049] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available products. To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0051] In Examples 1-5 and Comparative Examples 1-5, the nonionic surfactant was Tween 80 with an HLB value of 15.0, the conductivity of the deionized water was ≤0.1μS / cm, and the SiO2 was fumed silica with a particle size of 10-100nm.

[0052] The fluorinated paints used in Examples 1-5 and Comparative Examples 1-5 were from Chemours. Model number 857G-12002, the main components are: polytetrafluoroethylene, 2,6,8-trimethyl-4-nonoxyethylene oxyethanol, 2,6-dimethyl-4-heptanone, 5-chloro-2-methyl-1-isothiazolin-3-one, 2-methyl-1-isothiazolin-3-one and water.

[0053] The temperature difference between each zone of the heat treatment curing oven used in Examples 1-5 and Comparative Examples 1-5 is ≤5℃.

[0054] The metal substrates used in Examples 1-5 and Comparative Examples 1-5 are all 5025 aluminum alloy plates.

[0055] Example 1

[0056] A method for preparing a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating includes the following steps:

[0057] 1) Mix 0.2g Tween 80, 2g hydrogen-containing silicone oil, and 200g deionized water using a high-speed shear homogenizer at 5000rpm for 50min to obtain an oil-in-water emulsion.

[0058] 2) Pour the oil-in-water emulsion from step 1) into 1g of fumed silica and stir at 4600rpm×50min to obtain modified fumed silica slurry.

[0059] 3) After centrifuging the modified fumed silica slurry from step 2) at 5130 rpm for 8 min, the supernatant was removed and some water was removed to obtain 146.304 g of a viscous paste with a viscosity of 220 mPa·s, which is the modified paste.

[0060] 4) Take 20g of the modified paste from step 3) and pour it into 50g of fluorine-containing paint. Disperse it evenly by mechanical stirring, remove foam, and filter out large particulate impurities to obtain the modified paint. The stirring parameters are 1380rpm×5min and the filter screen accuracy is 100 mesh.

[0061] 5) Spray the modified paint from step 4) onto the surface of the 5025 aluminum alloy metal substrate at a spraying pressure of 0.2 MPa;

[0062] 6) Place the painted metal substrate from step 5) into a heat treatment furnace for curing. The furnace is placed at room temperature, and the heating rate is 35℃ / min. Finally, it is held at 420℃ for 25min.

[0063] In steps 1)-6), the amount of dust falling into the paint space should be controlled to be ≤10mg / m² per hour. 2 • h, the concentration of suspended particles with a diameter greater than 5 μm is ≤29 particles / m³ 3 .

[0064] Example 2

[0065] A method for preparing a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating includes the following steps:

[0066] 1) 0.5g Tween 80, 5g hydrogen-containing silicone oil and 200g deionized water were mixed using a high-speed shear homogenizer at 5000rpm×50min to obtain an oil-in-water emulsion.

[0067] 2) Pour the oil-in-water emulsion from step 1) into 5g of fumed silica and stir at 4750rpm for 50min to obtain modified fumed silica slurry.

[0068] 3) After centrifuging the modified fumed silica slurry from step 2) at 5060 rpm for 8 min, the supernatant was removed and some water was removed to obtain 151.560 g of viscous paste with a viscosity of 225 mPa·s, which is the modified paste.

[0069] 4) Take 20g of the modified paste from step 3) and pour it into 80g of fluorine-containing paint. Disperse it evenly by mechanical stirring, remove foam, and filter out large particulate impurities to obtain the modified paint. The stirring parameters are 1380rpm×5min and the filter screen accuracy is 100 mesh.

[0070] 5) Spray the modified paint from step 4) onto the surface of the 5025 aluminum alloy metal substrate at a spraying pressure of 0.2 MPa;

[0071] 6) Place the metal substrate that has been sprayed with paint in step 5) into a heat treatment furnace for curing. The furnace is placed at room temperature and the heating rate is 35℃ / min. Finally, it is held at 420℃ for 25min.

[0072] In steps 1)-6), the amount of dust falling into the paint space should be controlled to be ≤10mg / m² per hour. 2 • h, the concentration of suspended particles with a diameter greater than 5 μm is ≤29 particles / m³ 3 .

[0073] Example 3

[0074] A method for preparing a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating includes the following steps:

[0075] 1) Mix 1g Tween 80, 10g hydrogen-containing silicone oil and 200g deionized water using a high-speed shear homogenizer with stirring parameters of 5000rpm×50min to obtain an oil-in-water emulsion.

[0076] 2) Pour the oil-in-water emulsion from step 1) into 10g of fumed silica and stir at 5200rpm×50min to obtain modified fumed silica slurry.

[0077] 3) After centrifuging the modified fumed silica slurry from step 2) at 4780 rpm for 8 min, the supernatant was removed and some water was removed to obtain 159.120 g of viscous paste with a viscosity of 223 mPa·s, which is the modified paste.

[0078] 4) Take 20g of the modified paste from step 3) and pour it into 80g of fluorine-containing paint. Disperse it evenly by mechanical stirring, remove foam, and filter out large particulate impurities to obtain the modified paint. The stirring parameters are 1380rpm×5min and the filter screen accuracy is 100 mesh.

[0079] 5) Spray the modified paint from step 4) onto the surface of the 5025 aluminum alloy metal substrate at a spraying pressure of 0.3 MPa;

[0080] 6) Place the painted substrate from step 5) into a heat treatment furnace for curing. Place it in the furnace at room temperature, with a heating rate of 35℃ / min, and finally hold it at 420℃ for 25 minutes.

[0081] In steps 1)-6), the amount of dust falling into the paint space should be controlled to be ≤10mg / m² per hour. 2 • h, the concentration of suspended particles with a diameter greater than 5 μm is ≤29 particles / m³ 3 .

[0082] Example 4

[0083] A method for preparing a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating includes the following steps:

[0084] 1) Mix 1g Tween 80, 10g hydrogen-containing silicone oil and 200g deionized water using a high-speed shear homogenizer with stirring parameters of 5000rpm×50min to obtain an oil-in-water emulsion.

[0085] 2) Pour the oil-in-water emulsion from step 1) into 15g of fumed silica and stir at 5200rpm for 50min to obtain modified fumed silica slurry.

[0086] 3) After centrifuging the modified fumed silica slurry from step 2) at 4500 rpm for 8 min, the supernatant was removed and some water was removed to obtain 162.72 g of viscous paste with a viscosity of 222 mPa·s, which is the modified paste.

[0087] 4) Take 20g of the modified paste from step 3) and pour it into 80g of fluorine-containing paint. Disperse it evenly by mechanical stirring, remove foam, and filter out large particulate impurities to obtain the modified paint. The stirring parameters are 1380rpm×5min and the filter screen accuracy is 100 mesh.

[0088] 5) Spray the modified paint from step 4) onto the surface of the 5025 aluminum alloy metal substrate at a spraying pressure of 0.4 MPa.

[0089] 6) Place the painted substrate from step 5) into a heat treatment furnace for curing. Place it in the furnace at room temperature, with a heating rate of 35℃ / min, and finally hold it at 420℃ for 25 minutes.

[0090] In steps 1)-6), the amount of dust falling into the paint space should be controlled to be ≤10mg / m² per hour. 2 • h, the concentration of suspended particles with a diameter greater than 5 μm is ≤29 particles / m³ 3 .

[0091] Example 5

[0092] A method for preparing a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating includes the following steps:

[0093] 1) Mix 1g Tween 80, 10g hydrogen-containing silicone oil and 200g deionized water using a high-speed shear homogenizer with stirring parameters of 5000rpm×50min to obtain an oil-in-water emulsion.

[0094] 2) Pour the oil-in-water emulsion from step 1) into 20g of fumed silica and stir at 5200rpm for 50min to obtain modified fumed silica slurry.

[0095] 3) After centrifuging the modified fumed silica slurry from step 2) at 3600 rpm for 8 min, the supernatant was removed and some water was removed to obtain 166.32 g of viscous paste with a viscosity of 230 mPa·s, which is the modified paste.

[0096] 4) Take 20g of the modified paste from step 3) and pour it into 80g of fluorine-containing paint. Disperse it evenly by mechanical stirring, remove foam, and filter out large particulate impurities to obtain the modified paint. The stirring parameters are 1380rpm×5min and the filter screen accuracy is 100 mesh.

[0097] 5) Spray the modified paint from step 4) onto the surface of the 5025 aluminum alloy metal substrate at a spraying pressure of 0.4 MPa.

[0098] 6) Place the painted substrate from step 5) into a heat treatment furnace for curing. Place it in the furnace at room temperature, with a heating rate of 35℃ / min, and finally hold it at 420℃ for 25 minutes.

[0099] In steps 1)-6), the amount of dust falling into the paint space should be controlled to be ≤10mg / m² per hour. 2 • h, the concentration of suspended particles with a diameter greater than 5 μm is ≤29 particles / m³ 3 .

[0100] Comparative Example 1

[0101] A method for preparing a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating is exactly the same as in Example 5, except that the amount of fumed silica in step 2) is changed to 25g, the amount of modified paste obtained in step 3) is 169.92g, and the stirring parameters in step 4) are 2220rpm×20min.

[0102] Comparative Example 2

[0103] A method for preparing a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating is exactly the same as in Example 3, except that the amount of fluorinated paint in step 4) is changed to 50g.

[0104] Comparative Example 3

[0105] A method for preparing a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating is exactly the same as in Example 5, except that the amount of modified paste in step 4) is changed to 30g, the amount of fluorinated paint is changed to 70g, and the stirring parameters are changed to 2220rpm×20min.

[0106] Comparative Example 4

[0107] A method for preparing a hydrophobic, oleophobic, and wear-resistant fluorinated functional coating is exactly the same as in Example 4, except that the amount of fumed silica in step 2) is changed to 30g and the amount of modified paste obtained in step 3) is 173.52g.

[0108] Comparative Example 5

[0109] The fluorine-containing coating was not modified before being directly sprayed and cured after filtration.

[0110] Various tests were performed on the coatings prepared in Examples 1-5 and Comparative Examples 1-5 of the present invention, and the results are shown in Table 1.

[0111] Table 1 Performance parameters of the fluorine-containing functional coatings prepared in Examples 1-5 and Comparative Examples 1-5

[0112]

[0113] Note: In Comparative Examples 2 and 3, due to coating cracking, it was unnecessary to test the hydrophobic angle, oleophobic angle, and abrasion resistance, so these were not tested.

[0114] The distribution and morphology of SiO2 in the coating were tested using scanning electron microscopy (SEM) and EDT (see [reference]). Figure 5-13 (and to prove whether SiO2 is present in the coating).

[0115] According to GB / T 32095.1-2015 standard, fastness test, scratch test, friction test, and coating thickness, hydrophobic angle, and oleophobic angle tests were conducted to assess coating quality (see...). Figure 14-17 The hydrophobic angle and oleophobic angle are used to characterize the non-stick properties of the coating. When conducting friction tests, a scouring pad is used to rub the coating.

[0116] Passed the fastness test (see...) Figure 14 ), scratch test and friction test ( Figure 15 ), to test whether the coating is easy to peel off.

[0117] The wear resistance was analyzed by coating thickness testing.

[0118] Through tests of hydrophobicity and oleophobicity angles (see...) Figure 16 and 17The test is to determine whether the coating is hydrophobic and oleophobic.

[0119] Various tests revealed that the modified coatings in Examples 1-5 all possess both hydrophobic and oleophobic properties, as shown in Table 1. However, differences in the modification formulation and process resulted in variations in the uniformity of the coatings.

[0120] ① When the weight ratio of SiO2 particles in the coating does not exceed 2.29%, the coating quality is uniform, the silica in the coating is evenly dispersed, and no agglomeration occurs.

[0121] ② By comparing Comparative Example 1 and Example 5, it was found that when the proportion of silicon dioxide in the coating of Comparative Example 1 reached 2.78%, SiO2 agglomeration occurred, resulting in uneven protrusion of the coating.

[0122] ③ By comparing Example 2 and Example 3, it was found that when the ratio of modified paste to fluorinated paint reached 2:5, the SiO2 content in the coating was 1.73%, and the coating cracking defect appeared.

[0123] ④ By comparing Comparative Example 3 and Example 5, it was found that when the ratio of modified paste to fluorinated paint reached 3:7, the SiO2 content in the coating was 3.43%, and the coating cracking defect appeared.

[0124] ⑤ By comparing Comparative Example 4 with Example 4, it was found that when the proportion of silicon dioxide in the coating is 3.24%, defects such as uneven protrusion of the coating caused by SiO2 agglomeration also occur.

[0125] ⑥ Comparative Example 5 shows that when the coating is not modified, the oleophobic angle is only 12° and it does not have oleophobic function, while the hydrophobic angle is 112° and it has a certain hydrophobic function. The wear resistance is 6500 cycles, as shown in Table 1.

[0126] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A hydrophobic, oleophobic, and wear-resistant fluorinated functional coating, characterized in that, The coating comprises a modified paste and a fluorinated paint, wherein the mass ratio of the modified paste to the fluorinated paint is 2:8; The modified paste comprises fumed silica and an oil-in-water emulsion, wherein the mass ratio of fumed silica to oil-in-water emulsion is 0.8-19:200; and the weight proportion of fumed silica in the coating does not exceed 2.29%. The oil-in-water emulsion comprises, by weight, 3.8-5.6 wt% hydrogen-containing silicone oil, 0.38-0.45 wt% nonionic surfactant, and the balance being deionized water.

2. The hydrophobic, oleophobic, and wear-resistant fluorinated functional coating according to claim 1, characterized in that, The fluorinated paint contains polytetrafluoroethylene, 2,6,8-trimethyl-4-nonoxyethylene ethanol, 2,6-dimethyl-4-heptanone, 5-chloro-2-methyl-1-isothiazolin-3-one, 2-methyl-1-isothiazolin-3-one, and water.

3. The hydrophobic, oleophobic, and wear-resistant fluorinated functional coating according to claim 1, characterized in that, The fumed silica has a particle size of 10-100 nm; the nonionic surfactant has an HLB value of 15.0-15.6; and the deionized water has a conductivity of ≤0.1 μS / cm.

4. The method for preparing the hydrophobic, oleophobic, and wear-resistant fluorinated functional coating according to any one of claims 1-3, characterized in that, Includes the following steps: Step S1: Mechanically stir the modified paste and fluorine-containing paint to disperse them evenly at a stirring speed of 1800-3200 rpm; Step S2: After stirring, the paint obtained is defoamed, filtered and large particulate impurities are removed to obtain modified paint. The modified paint is then atomized and sprayed onto the designated surface of the part. Step S3: Perform high-temperature curing and sintering treatment on the sprayed parts to obtain a coating with a hydrophobic angle ≥120°, an oleophobic angle ≥110°, and a wear resistance cycle ≥6500.

5. The method for preparing the hydrophobic, oleophobic, and wear-resistant fluorinated functional coating according to claim 4, characterized in that, The preparation method of the modified paste in step S1 includes the following steps: (1) Hydrogen-containing silicone oil, nonionic surfactant, and deionized water are mixed and stirred at a high speed of 4600-5200 rpm to obtain an oil-in-water microemulsion. (2) The obtained oil-in-water microemulsion was added to fumed silica and stirred at a high speed of 4600-5200 rpm to obtain modified fumed silica slurry. (3) After centrifuging the obtained modified fumed silica slurry, the supernatant is removed and some water is removed to make a modified paste. The viscosity of the modified paste is 100-500 mPa·s.

6. The method for preparing the hydrophobic, oleophobic, and wear-resistant fluorinated functional coating according to claim 4, characterized in that, In step S2, the paint is atomized and sprayed onto the surface of a metal substrate with a hardness of 40-135 HB, and the spraying pressure during atomization is 0.2-0.4 MPa.

7. The method for preparing the hydrophobic, oleophobic, and wear-resistant fluorinated functional coating according to claim 4, characterized in that, The process parameters for the high-temperature curing and sintering treatment described in step S3 are as follows: room temperature furnace entry, heating rate < 40℃ / min, final curing temperature 360-420℃, holding time to film thickness ratio 0.5-1min / μm, and heat sources and insulation components distributed as needed in the furnace to control temperature fluctuations in each zone ≤ ±5℃.

8. The method for preparing the hydrophobic, oleophobic, and wear-resistant fluorinated functional coating according to claim 4, characterized in that, In steps S1-S3, the amount of dust falling into the paint space is controlled, with the hourly dust amount ≤10mg / m³. 2 • h, the concentration of suspended particles with a diameter greater than 5 μm is ≤29 particles / m³ 3 .

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