Superhydrophobic self-cleaning coating and preparation thereof and coating and applications based thereon

Abstract

The present application belongs to the technical field of self-cleaning coating material, and discloses a super-hydrophobic self-cleaning coating material, a preparation method thereof, and a coating based on the same and application. The super-hydrophobic self-cleaning coating material comprises paint phenol, amino silicone oil and mixed solvents. The present application realizes the chemical modification of the paint phenol by the amino silane through the chemical reaction between the groups of the paint phenol and the amino silane. Further, the present application uses ethanol and water as mixed solvents, utilizes the compatibility difference of the paint phenol and the amino silicone oil in the ethanol and water, and assembles the microstructure in the solvent drying and volatilization process during the application process, which is unique and avoids the limitations of the traditional method of constructing microstructure by using nanoparticles. Further, the hydrophobic long chain of the paint phenol and the hydrophobic silicone chain segment of the amino silicone oil are utilized, so as to endow the material surface with excellent low surface energy characteristics.

Description

Technical Field

[0001] This invention belongs to the field of self-cleaning coating materials technology, and specifically relates to a superhydrophobic self-cleaning coating, its preparation method, and coatings and applications based thereon. Background Technology

[0002] There are many superhydrophobic biological phenomena in nature, the most representative of which is the "lotus effect". The surface of a lotus leaf is highly hydrophobic, with a static contact angle greater than 150°. Moreover, the adhesion force of water droplets to the surface of a lotus leaf is very small, and water droplets can easily roll off the surface of a lotus leaf. At the same time, it can carry away the dust on the surface of the lotus leaf, achieving the purpose of "self-cleaning". This phenomenon is called the "lotus effect".

[0003] In recent years, superhydrophobic surfaces have attracted widespread attention from scientists and engineers both domestically and internationally due to their unique wettability and self-cleaning properties. Microscopic analysis of these surfaces reveals two key factors contributing to their formation: a micro / nano composite structure with high surface roughness and materials with low surface energy. Based on biomimetic principles and relevant theoretical frameworks of superhydrophobicity, various superhydrophobic materials have been fabricated and have achieved promising applications.

[0004] However, many problems still need to be solved in the practical application of superhydrophobic self-cleaning coatings. These include cumbersome preparation processes, specialized equipment, unsuitability for large-area substrates, poor resistance to mechanical wear, and poor hydrophobicity retention, all of which hinder the widespread application of superhydrophobic materials. Therefore, superhydrophobic materials that are low-cost, pollution-free, simple to prepare, readily available, and have stable performance urgently need attention and development.

[0005] Urushiol is the main component of raw lacquer, accounting for about 70% of its mass. It is a catechol derivative with straight-chain alkyl groups of varying saturation (0-3%). The long side chain structure provides excellent hydrophobic properties. As an important forest product in my country, the effective utilization and development of raw lacquer resources, and the enhancement of the added value of raw lacquer materials, are of great significance. Summary of the Invention

[0006] In order to overcome the shortcomings and deficiencies of the prior art, the primary objective of this invention is to provide a superhydrophobic self-cleaning coating.

[0007] Another objective of this invention is to provide a method for preparing the above-mentioned superhydrophobic self-cleaning coating.

[0008] Another objective of this invention is to provide a superhydrophobic self-cleaning coating based on the above-mentioned superhydrophobic self-cleaning coating.

[0009] Another object of the present invention is to provide the application of the above-mentioned superhydrophobic self-cleaning coating.

[0010] The objective of this invention is achieved through the following solution:

[0011] A superhydrophobic self-cleaning coating, comprising urushiol, amino silicone oil and mixed solvents.

[0012] Furthermore, the mass ratio of urushiol to amino silicone oil can be (5-30):(1-10).

[0013] Furthermore, the mass ratio of urushiol to amino silicone oil can be 3:1 to 1:2.

[0014] Furthermore, the mixed solvent is ethanol and water.

[0015] Furthermore, the mass ratio of ethanol to water can be 100:10 to 100:30.

[0016] Furthermore, the mass ratio of ethanol to urushiol can be 100:5-100:30.

[0017] Furthermore, the viscosity of the amino silicone oil can be 500-15000 mPa·s.

[0018] Furthermore, the ammonia value of the amino silicone oil can be 0.2-0.8 mmol / g.

[0019] This invention provides a method for preparing the above-mentioned superhydrophobic self-cleaning coating, comprising adding urushiol to a mixed solvent of ethanol and water to obtain a urushiol solution, then adding amino silicone oil, stirring evenly, and obtaining a superhydrophobic self-cleaning coating.

[0020] The raw materials of the superhydrophobic self-cleaning coating of this invention are green and environmentally friendly, abundant in source, low in cost, and free of fluorine. By coating the substrate surface with these materials, a superhydrophobic self-cleaning coating can be quickly obtained. The preparation process is simple, and the resulting coating can achieve a water droplet contact angle of 162°, exhibiting excellent superhydrophobic self-cleaning properties.

[0021] The present invention also provides the application of the above-mentioned superhydrophobic self-cleaning coating in surface hydrophobic modification.

[0022] The present invention also provides a coating based on the above-mentioned superhydrophobic self-cleaning coating, wherein the superhydrophobic self-cleaning coating is applied to the surface of a substrate and dried to obtain the superhydrophobic self-cleaning coating.

[0023] Furthermore, the drying can be carried out at 25-80°C.

[0024] Furthermore, the drying time can be 5-48 hours.

[0025] Furthermore, the superhydrophobic self-cleaning coating is pretreated by heating and stirring before use.

[0026] Furthermore, the temperature for the heating pretreatment can be 35-65℃.

[0027] Furthermore, the heating pretreatment time can be 1-5 hours of stirring.

[0028] Furthermore, the coating method can be spraying, brushing, etc.

[0029] This invention utilizes the chemical reaction between the groups of urushiol and aminosilane to achieve the chemical modification of urushiol by aminosilane. Furthermore, this invention uses ethanol and water as a mixed solvent, taking advantage of the compatibility difference between urushiol and aminosilicone in ethanol and water. During the application process, the two can assemble microstructures during the solvent drying and evaporation process, which is a unique approach and avoids the limitations of traditional methods that use nanoparticles to construct microstructures. Furthermore, it utilizes the hydrophobic long chains of urushiol and the hydrophobic siloxane segments of aminosilicone to endow the material surface with excellent low surface energy properties.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] 1. This invention utilizes urushiol and amino silicone oil as low surface energy raw materials, and further uses ethanol and water as mixed solvents to achieve controlled assembly to obtain a surface with a special micro-nano structure, thus preparing a superhydrophobic self-cleaning coating surface.

[0032] 2. The coating and coating based thereon of the present invention have a simple preparation process, low cost, green and environmentally friendly raw materials that are free of fluorine, can be prepared quickly, and the surface properties of the prepared coating are stable. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 The image shows the water droplet contact angle test result on the surface of the superhydrophobic self-cleaning coating prepared in Example 1.

[0035] Figure 2 The image shows the SEM image of the surface of the superhydrophobic self-cleaning coating prepared in Example 1.

[0036] Figure 3 SEM image of the surface of the functional coating prepared in Comparative Example 1.

[0037] Figure 4 SEM image of the surface of the functional coating prepared in Comparative Example 2. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Unless otherwise specified, all materials involved in the following embodiments are commercially available. Unless otherwise specified, all methods described are conventional methods.

[0039] The key concept of this invention is: by using ethanol and water as a mixed solvent, and taking advantage of the compatibility differences between urushiol and amino silicone oil in water and ethanol, respectively, surface microstructures can be assembled during the solvent drying and evaporation process; further, by utilizing the hydrophobic long chains of urushiol and amino silicone oil themselves and the chemical reaction between the two, a self-cleaning coating surface with superhydrophobic properties is finally obtained.

[0040] One embodiment is a superhydrophobic self-cleaning coating, the components of which include urushiol, amino silicone oil and mixed solvent.

[0041] In one embodiment, the mass ratio of urushiol to amino silicone oil is (5-30):(1:10). In another embodiment, the mass ratio of urushiol to amino silicone oil is 3:1-1:2; in yet another embodiment, the mass ratio of urushiol to amino silicone oil is 1:2; and in still another embodiment, the mass ratio of urushiol to amino silicone oil is 3:1.

[0042] In one embodiment, the mixed solvent is ethanol and water.

[0043] In one embodiment, the mass ratio of ethanol to water is 100:10-100:30. In one embodiment, the mass ratio of ethanol to water is 100:20; in another embodiment, the mass ratio of ethanol to water is 100:15; and in yet another embodiment, the mass ratio of ethanol to water is 100:10.

[0044] In one embodiment, the mass ratio of ethanol to urushiol is 100:5-100:30. In one embodiment, the mass ratio of ethanol to urushiol is 100:5; in another embodiment, the mass ratio of ethanol to urushiol is 100:25; and in yet another embodiment, the mass ratio of ethanol to urushiol is 100:10.

[0045] In one embodiment, the viscosity of the amino silicone oil is 500-15000 mPa·s. In another embodiment, the viscosity of the amino silicone oil is 3500 mPa·s; in yet another embodiment, the viscosity of the amino silicone oil is 5000 mPa·s.

[0046] In one embodiment, the amino silicone oil has an ammonia value of 0.2-0.8 mmol / g. In another embodiment, the amino silicone oil has an ammonia value of 0.3 mmol / g; in yet another embodiment, the amino silicone oil has an ammonia value of 0.4 mmol / g; and in still another embodiment, the amino silicone oil has an ammonia value of 0.6 mmol / g.

[0047] In another embodiment, a method for preparing a superhydrophobic self-cleaning coating includes adding urushiol to a mixed solvent of ethanol and water to obtain a urushiol solution, then adding amino silicone oil and stirring evenly to obtain a superhydrophobic self-cleaning coating.

[0048] Another embodiment is the application of superhydrophobic self-cleaning coatings in surface hydrophobic modification.

[0049] In another embodiment, a coating based on the above-mentioned superhydrophobic self-cleaning coating is obtained by applying the superhydrophobic self-cleaning coating to the surface of a substrate and drying it.

[0050] In one embodiment, the drying is carried out at 25-80°C.

[0051] In one embodiment, the drying time is 5-48 hours.

[0052] In one embodiment, the superhydrophobic self-cleaning coating is pretreated by heating and stirring before use.

[0053] In one embodiment, the temperature of the heating pretreatment is 35-65°C.

[0054] In one embodiment, the heating pretreatment time is 1-5 hours of stirring.

[0055] In one embodiment, the coating method is spraying, brushing, etc.

[0056] The raw materials of the superhydrophobic self-cleaning coating of this invention are green and environmentally friendly, abundant in source, low in cost, and free of fluorine. By coating the substrate surface with these materials, a superhydrophobic self-cleaning coating can be quickly obtained. The preparation process is simple, and the resulting coating can achieve a water droplet contact angle of 162°, exhibiting excellent superhydrophobic self-cleaning properties.

[0057] This invention utilizes the chemical reaction between the groups of urushiol and aminosilane to achieve the chemical modification of urushiol by aminosilane. Using ethanol and water as a mixed solvent, this invention leverages the compatibility differences between urushiol and aminosilicone in ethanol and water. During application, the two can assemble microstructures during solvent drying and evaporation, offering a unique approach and avoiding the limitations of traditional methods that use nanoparticles to construct microstructures. Furthermore, by utilizing the hydrophobic long chains of urushiol and the hydrophobic siloxane segments of aminosilicone, the invention endows the material surface with excellent low surface energy properties.

[0058] As described above, the use of ethanol and water as a mixed solvent, and the precise mass ratio of ethanol and water with urushiol and amino silicone oil, are crucial for the formation of the superhydrophobic self-cleaning coating. A suitable raw material ratio is beneficial for the assembly and formation of micro / nano structures on the coating surface. The raw materials used in this invention are abundant, environmentally friendly, and fluorine-free.

[0059] Example 1

[0060] (1) Mix 100 parts by mass of ethanol, 20 parts by mass of water and 20 parts by mass of urushiol (Pingli small wood lacquer, commercially available, place of origin: Ankang, Shaanxi) evenly to prepare urushiol solution.

[0061] (2) 5 parts by mass of amino silicone oil (Dow Corning OFX-8040, ammonia value 0.4, viscosity 3500) were added to urushiol solution and pretreated by heating and stirring to obtain coating solution; the temperature of the heating pretreatment was 45℃ and the time was 4h.

[0062] (3) Apply the coating solution to the substrate surface and dry it at 60°C for 12 hours to obtain a superhydrophobic self-cleaning coating.

[0063] The test results are as follows: Figure 1 As shown, the water droplet contact angle on the surface of the superhydrophobic self-cleaning coating prepared by this invention is 160°, achieving a superhydrophobic state, and the material surface exhibits good superhydrophobic self-cleaning effect. The microstructure of the functional coating surface was observed, as shown... Figure 2 As shown in the figure, the functional coating surface prepared by this invention exhibits a distinct micro-nano structure. This unique micro-nano structure contributes to improving the hydrophobicity and water droplet contact angle of the coating surface.

[0064] Example 2

[0065] (1) Mix 100 parts by mass of ethanol, 15 parts by mass of water and 10 parts by mass of urushiol (same as in Example 1) evenly to prepare urushiol solution.

[0066] (2) 5 parts by mass of amino silicone oil (Dow Corning OFX-8468, ammonia value 0.6, viscosity 15000) were added to urushiol solution and pretreated by heating and stirring to obtain coating solution; the heating pretreatment temperature was 55℃ and the time was 5h.

[0067] (3) Apply the coating solution to the substrate surface and dry it at 80°C for 5 hours to obtain a superhydrophobic self-cleaning coating.

[0068] Tests showed that the water droplet contact angle on the surface of the superhydrophobic self-cleaning coating prepared in this embodiment was 150°, achieving a superhydrophobic state. The coating surface has obvious micro-nano structures, and the material surface has excellent superhydrophobic self-cleaning effect.

[0069] Example 3

[0070] (1) Mix 100 parts by mass of ethanol, 10 parts by mass of water and 30 parts by mass of urushiol (same as in Example 1) evenly to prepare a urushiol solution.

[0071] (2) 10 parts by mass of amino silicone oil (Wacker WT1650, ammonia value 0.6) was added to urushiol solution and heated and stirred for pretreatment to obtain coating solution; the heating pretreatment temperature was 35℃ and the time was 5h.

[0072] (3) Apply the coating solution to the substrate surface and dry it at 80°C for 5 hours to obtain a superhydrophobic self-cleaning coating.

[0073] Tests showed that the water droplet contact angle on the surface of the superhydrophobic self-cleaning coating prepared in this embodiment was 155°, achieving a superhydrophobic state. The coating surface has obvious micro-nano structures, and the material surface has excellent superhydrophobic self-cleaning effect.

[0074] Example 4

[0075] (1) Mix 100 parts by mass of ethanol, 30 parts by mass of water and 5 parts by mass of urushiol (same as in Example 1) evenly to prepare a urushiol solution.

[0076] (2) 10 parts by mass of amino silicone oil (Wacker WR301, ammonia value 0.3, viscosity 800 mPa) was added to urushiol solution and pretreated by heating and stirring to obtain coating solution; the temperature of the pretreatment was 65°C and the time was 1 h.

[0077] (3) Apply the coating solution to the substrate surface and dry it at 25°C for 48 hours to obtain a superhydrophobic self-cleaning coating.

[0078] Tests showed that the water droplet contact angle on the surface of the superhydrophobic self-cleaning coating prepared in this embodiment was 160°, achieving a superhydrophobic state. The coating surface has obvious micro-nano structures, and the material surface has excellent superhydrophobic self-cleaning effect.

[0079] Example 5

[0080] (1) Mix 100 parts by mass of ethanol, 13 parts by mass of water and 25 parts by mass of urushiol (high mountain wood lacquer, commercially available, place of origin: Ankang, Shaanxi) evenly to prepare urushiol solution.

[0081] (2) Add 8 parts by mass of amino silicone oil (Wacker WR301, ammonia value 0.3, viscosity 800 mPa) to urushiol solution and perform heating and stirring pretreatment to obtain coating solution; the heating pretreatment temperature is 45℃ and the time is 5h.

[0082] (3) Apply the coating solution to the substrate surface and dry it at 70°C for 24 hours to obtain a superhydrophobic self-cleaning coating.

[0083] Tests showed that the water droplet contact angle on the surface of the superhydrophobic self-cleaning coating prepared in this embodiment was 162°, achieving a superhydrophobic state. The coating surface has obvious micro-nano structures, and the material surface has excellent superhydrophobic self-cleaning effect.

[0084] Example 6

[0085] (1) Mix 100 parts by mass of ethanol, 15 parts by mass of water and 20 parts by mass of urushiol (high mountain wood lacquer, commercially available, place of origin: Ankang, Shaanxi) evenly to prepare urushiol solution.

[0086] (2) 10 parts by mass of amino silicone oil (Dow Corning OFX-8468, ammonia value 0.6, viscosity 5000) was added to urushiol solution and pretreated by heating and stirring to obtain coating solution; the heating pretreatment temperature was 45℃ and the time was 5h.

[0087] (3) Apply the coating solution to the substrate surface and dry it at 80°C for 48 hours to obtain a superhydrophobic self-cleaning coating.

[0088] Tests showed that the water droplet contact angle on the surface of the superhydrophobic self-cleaning coating prepared in this embodiment was 152°, achieving a superhydrophobic state. The coating surface has obvious micro-nano structures, and the material surface has excellent superhydrophobic self-cleaning effect.

[0089] Comparative Example 1

[0090] Referring to the method of Example 1, water is not introduced as a solvent into the system. That is:

[0091] (1) Mix 100 parts by mass of ethanol and 20 parts by mass of urushiol (Pingli small wood lacquer, commercially available, place of origin: Ankang, Shaanxi) evenly to prepare urushiol solution;

[0092] (2) 5 parts by mass of amino silicone oil (Dow Corning OFX-8040, ammonia value 0.4, viscosity 3500) were added to urushiol solution and pretreated by heating and stirring to obtain coating solution; the temperature of the heating pretreatment was 45℃ and the time was 4h.

[0093] (3) Apply the coating solution to the surface of the substrate and dry it at 60°C for 12 hours to obtain the functional coating.

[0094] Testing revealed that the water droplet contact angle on the prepared functional coating material surface was 98°, failing to achieve a superhydrophobic state. Observation of the microstructure of the functional coating surface revealed... Figure 3 As shown in the figure, the prepared functional coating surface is relatively uniform and smooth, without obvious microstructure. This demonstrates that the introduction of water in the mixed solvent system of ethanol and water is crucial for the formation of the microstructure on the coating surface of this invention.

[0095] Comparative Example 2

[0096] Referring to the method in Example 1, the amount of water used in the system was varied. That is:

[0097] (1) Mix 100 parts by mass of ethanol, 5 parts by mass of water and 20 parts by mass of urushiol (Pingli small wood lacquer, commercially available, place of origin: Ankang, Shaanxi) evenly to prepare urushiol solution.

[0098] (2) 5 parts by mass of amino silicone oil (Dow Corning OFX-8040, ammonia value 0.4, viscosity 3500) were added to urushiol solution and pretreated by heating and stirring to obtain coating solution; the temperature of the heating pretreatment was 45℃ and the time was 4h.

[0099] (3) Apply the coating solution to the surface of the substrate and dry it at 60°C for 12 hours to obtain the functional coating.

[0100] Testing revealed that the water droplet contact angle on the prepared functional coating material was 125°, a significant improvement compared to Comparative Example 1, but still not reaching a superhydrophobic state. Observation of the microstructure of the functional coating surface revealed... Figure 4 As shown in the figure, the prepared functional coating surface has a certain micro-nano structure, which is beneficial to improving the hydrophobicity of the coating and exhibiting a high water droplet contact angle. Therefore, compared with Example 1 and Comparative Example 1, it can be seen that the amount of water used in the system changes the microstructure and hydrophobicity of the coating surface.

[0101] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A superhydrophobic self-cleaning coating, characterized in that... The components include urushiol, amino silicone oil, and a mixed solvent; the mass ratio of urushiol to amino silicone oil is (5-30):(1-10); the mixed solvent is ethanol and water; the mass ratio of ethanol to water is 100:10-100:30; the mass ratio of ethanol to urushiol is 100:5-100:30; the viscosity of the amino silicone oil is 500-15000 mPa·s; and the ammonia value of the amino silicone oil is 0.2-0.8 mmol / g.

2. A method for preparing the superhydrophobic self-cleaning coating according to claim 1, characterized in that... The process involves adding urushiol to a mixed solvent of ethanol and water to obtain a urushiol solution, then adding amino silicone oil and stirring until homogeneous to obtain a superhydrophobic self-cleaning coating.

3. The application of the hydrophobic self-cleaning coating according to claim 1 in surface hydrophobic modification.

4. A coating based on the hydrophobic self-cleaning coating of claim 1, characterized in that... By applying the hydrophobic self-cleaning coating of claim 1 to the surface of a substrate and drying it, a superhydrophobic self-cleaning coating is obtained.

5. The coating according to claim 4, characterized in that: The drying is carried out at 25-80℃; the drying time is 5-48 hours.

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