WO2019062083A1

WO2019062083A1 - Superhydrophobic coating layer, preparation method therefor and application thereof

Info

Publication number: WO2019062083A1
Application number: PCT/CN2018/083684
Authority: WO
Inventors: 刘若鹏; 赵治亚; 肖成伟
Original assignee: 洛阳尖端技术研究院; 洛阳尖端装备技术有限公司
Priority date: 2017-09-28
Filing date: 2018-04-19
Publication date: 2019-04-04
Also published as: CN109575738A

Abstract

A superhydrophobic coating layer having a self-cleaning capability, the preparation method comprising: adding fluorine-containing silicon polyacrylate, tetraethyl orthosilicate, methyltriethoxysilane, ethanol and ammonia water into a container to obtain a mixed liquid, and reacting the mixed liquid to obtain a hybrid emulsion (1); spraying the hybrid emulsion onto a surface (3) of a substrate by means of a spray gun (2); drying to obtain a superhydrophobic coating layer (4).

Description

Superhydrophobic coating and preparation method and application thereof

Technical field

The present invention relates to hydrophobic materials and, more particularly, to superhydrophobic coatings having self-cleaning properties, and methods of making and using same.

Background technique

At present, extensive research has been carried out on superhydrophobic self-cleaning materials at home and abroad. Most of the existing solutions have surface modification of the substrate by low surface energy materials, which can make the surface of the substrate have a certain degree of hydrophobic property and is expected to achieve self-cleaning effect; however, the self-cleaning test results show that although the surface of the substrate It has a certain degree of hydrophobic properties, but its self-cleaning effect is not ideal. At the same time, the self-cleaning effect of this hydrophobic coating gradually decreases during repeated use, so the durability of the hydrophobic self-cleaning coating is also an important factor in measuring its self-cleaning effect. In addition, the traditional self-cleaning coating process is complicated and costly, which is not conducive to large-scale production preparation, thereby limiting its development and application.

Summary of the invention

The invention discloses a superhydrophobic coating with self-cleaning properties. The invention improves the self-cleaning effect of the super-hydrophobic coating layer under the low cost condition, has strong durability, and has simple preparation process, and is favorable for large-area production preparation.

The invention provides a method for preparing a superhydrophobic coating comprising: adding fluorine-containing silicon polyacrylate (FSiPA), tetraethyl orthosilicate (TEOS), methyltriethoxysilane (MTES), to a vessel, Ethanol and aqueous ammonia are used to obtain a mixed solution; the mixed liquid is reacted to obtain a hybrid emulsion; and the hybrid emulsion is sprayed on the surface of the substrate and dried to obtain the superhydrophobic coating.

In the above method, the fluorine-containing polyacrylic acid ester accounts for 5% to 25% by mass in the mixed liquid.

In the above method, the ratio of the amounts of the substances of tetraethyl orthosilicate, methyltriethoxysilane, ethanol and aqueous ammonia is 1:3-7:40-60:5-15.

In the above method, the ratio of the amounts of the substances of tetraethyl orthosilicate, methyltriethoxysilane, ethanol and aqueous ammonia is 1:5:50:10.

In the above method, after adding fluorine-containing silicon polyacrylate, tetraethyl orthosilicate, methyltriethoxysilane, ethanol and ammonia water to the vessel, stirring is carried out at 200-400 r/min to obtain the Mixture.

In the above method, wherein the reaction is carried out for a period of from 5 to 7 hours.

In the above method, wherein the nozzle of the spray gun used for the spraying is at a distance of 15 to 30 cm from the substrate.

In the above method, wherein the drying is drying at room temperature for 12 to 36 hours.

In the above method, wherein the superhydrophobic coating layer has a thickness of 0.1 to 0.5 mm.

In the above method, wherein the substrate is a glass substrate.

The present invention also provides a superhydrophobic coating prepared according to the above method.

The invention also provides a glass, wherein the glass comprises the superhydrophobic coating described above.

The present invention also provides an anti-icing device, wherein the anti-icing device comprises the superhydrophobic coating described above.

The present invention also provides a self-cleaning device, wherein the self-cleaning device comprises the superhydrophobic coating described above.

The invention also provides the above-mentioned application of the superhydrophobic coating in the fields of automobile, building materials, lamps, glass, ceramics, stainless steel, aluminum alloy, solar photovoltaic, aerospace.

The invention improves the self-cleaning effect and durability performance of the hydrophobic coating, and can be directly sprayed on the surface of the substrate without heating and curing, and has the characteristics of simple manufacturing process and large-area preparation. The FSiPA used in the present invention can help the coating to form a film well, thereby enhancing the durability of the coating without adversely affecting the hydrophobicity of the coating. The addition of TEOS helps to increase the roughness of the coating on the surface of the substrate, thereby increasing the hydrophobicity of the coating and achieving self-cleaning. The MTES can hydrophobically modify the SiO ₂ particles produced by TEOS hydrolysis, which helps to improve the hydrophobic properties of the coating.

DRAWINGS

1 is a schematic flow chart showing the preparation of a superhydrophobic coating having self-cleaning properties according to the present invention, wherein 1 is a SiO ₂ /fluorosilicon polyacrylate hybrid emulsion, 2 is a spray gun, 3 is a substrate, and 4 is A superhydrophobic coating formed on the substrate.

Detailed ways

The coating of the present invention is prepared by preparing a fluorine-containing silicone polyacrylate (FSiPA) by semi-continuous seed emulsion polymerization; a certain amount of FSiPA, tetraethyl orthosilicate (TEOS), methyltriethoxy Silane (MTES), ethanol and ammonia are mixed uniformly to obtain a mixed solution, and the mixed solution is reacted to obtain a SiO ₂ /fluorosilicon polyacrylate hybrid emulsion; the hybrid emulsion is uniformly sprayed on the substrate to maintain the nozzle and the substrate of the spray gun. The distance is 15-30cm, and a super-hydrophobic coating with self-cleaning properties can be obtained after the surface of the substrate is dried. The thickness of the coating is controlled from 0.1 mm to 0.5 mm.

Referring to Fig. 1, a SiO ₂ /fluorosilicon polyacrylate hybrid emulsion 1 is sprayed on a substrate 3 via a spray gun 2, and dried to obtain a superhydrophobic coating 4. After that, an ultraviolet aging test, a contact angle test, and the like can be performed.

The tetraethyl orthosilicate (TEOS), methyltriethoxysilane (MTES), ethanol, and ammonia water used in the present invention all reach an analytical grade. The amount of FSiPA used affects the film-forming properties of the coating and the contact angle of the coating with water (WCA). The SiO ₂ particles produced by the hydrolysis of TEOS can build a micro/nano structure on the surface of the substrate, thereby increasing the surface of the material. The degree of roughness; the addition of FSiPA can improve the bonding performance between the hydrophobic SiO ₂ particles, that is, the addition of FSiPA can embed the SiO ₂ particles into the latex film formed by FSiPA, so that the film forming performance of the coating is greatly improved. However, the excessive amount of FSiPA will reduce the roughness of the coating surface. Since the surface roughness is one of the important factors that make the coating superhydrophobic, the hydrophobicity of the coating is degraded. The ratio of TEOS to MTES has an effect on the hydrophobic properties of the coating. This is because MTES can hydrophobically modify the SiO ₂ particles produced by TEOS hydrolysis, which helps to improve the hydrophobic properties of the coating. In the present invention, the ratio of FSIPA to the weight ratio in the mixed solution is 5% to 25%, and the ratio of the amount of the material of tetraethyl orthosilicate (TEOS), methyltriethoxysilane (MTES), ethanol, and ammonia is used. It is 1:3-7:40-60:5-15.

The invention will now be described in conjunction with specific embodiments for a better understanding of the invention.

Example 1

Quantitative FSiPA emulsion, TEOS, MTES, C ₂ H ₅ OH and NH ₃ ·H ₂ O were added to the three-necked flask to obtain a mixed solution. The weight content of the FSiPA emulsion was 15%, TEOS, MTES, C ₂ H ₅ OH The ratio of the amount of the substance to NH ₃ ·H ₂ O is 1:3:50:10. At room temperature, the mixture was stirred at 300 r/min. After 6 h of reaction, a hybrid emulsion was obtained. The emulsion was sprayed on the surface of a clean and dry glass substrate, and the distance between the nozzle of the spray gun and the substrate was kept at 25 cm. After drying for 24 h, a superhydrophobic coating with self-cleaning effect can be obtained on the surface of the glass substrate after the surface is completely dried.

Example 2

Quantitative FSiPA emulsion, TEOS, MTES, C ₂ H ₅ OH and NH ₃ ·H ₂ O were added to the three-necked flask to obtain a mixed solution. The weight content of the FSiPA emulsion was 15%, TEOS, MTES, C ₂ H ₅ OH The ratio of the amount of the substance to NH ₃ ·H ₂ O is 1:5:50:8. At room temperature, the mixture was stirred at 200 r/min. After 6 h of reaction, a hybrid emulsion was obtained. The emulsion was sprayed on the surface of a clean and dry glass substrate, and the distance between the nozzle of the spray gun and the substrate was kept at 25 cm. After drying for 24 h, a superhydrophobic coating with self-cleaning effect can be obtained on the surface of the glass substrate after the surface is completely dried.

Example 3

Quantitative FSiPA emulsion, TEOS, MTES, C ₂ H ₅ OH and NH ₃ ·H ₂ O were added to the three-necked flask to obtain a mixed solution. The weight content of the FSiPA emulsion was 5%, TEOS, MTES, C ₂ H ₅ OH The ratio of the amount of the substance to NH ₃ ·H ₂ O is 1:4:40:5. At room temperature, the mixture was stirred at 250 r/min, and after 5 h of reaction, a hybrid emulsion was obtained. The emulsion was sprayed on the surface of a clean and dry glass substrate, and the distance between the nozzle of the spray gun and the substrate was kept at 20 cm, and placed at room temperature. After drying for 18 h, a superhydrophobic coating with self-cleaning effect can be obtained on the surface of the glass substrate after the surface is completely dried.

Example 4

Quantitative FSiPA emulsion, TEOS, MTES, C ₂ H ₅ OH and NH ₃ ·H ₂ O were added to the three-necked flask to obtain a mixed solution. The weight content of the FSiPA emulsion was 20%, TEOS, MTES, C ₂ H ₅ OH The ratio of the amount of the substance to NH ₃ ·H ₂ O is 1:5:45:10. At room temperature, the mixture was stirred at 350 r/min. After 7 h of reaction, a hybrid emulsion was obtained. The emulsion was sprayed on the surface of a clean and dry glass substrate, and the distance between the nozzle of the spray gun and the substrate was kept at 15 cm. After drying for 12 h, a superhydrophobic coating with self-cleaning effect can be obtained on the surface of the glass substrate after the surface is completely dried.

Example 5

Quantitative FSiPA emulsion, TEOS, MTES, C ₂ H ₅ OH and NH ₃ ·H ₂ O were added to the three-necked flask to obtain a mixed solution. The weight content of the FSiPA emulsion was 10%, TEOS, MTES, C ₂ H ₅ OH The ratio of the amount of the substance to NH ₃ ·H ₂ O is 1:6:55:13. At room temperature, stir the mixture at 400r/min, and obtain a hybrid emulsion after 5h reaction. Spray the emulsion on the surface of the clean and dry glass substrate, keep the distance between the nozzle of the spray gun and the substrate at 30cm, and put it at room temperature. After drying for 32 h, a superhydrophobic coating with self-cleaning effect can be obtained on the surface of the glass substrate after the surface is completely dried.

Example 6

Quantitative FSiPA emulsion, TEOS, MTES, C ₂ H ₅ OH and NH ₃ ·H ₂ O were added to the three-necked flask to obtain a mixed solution. The weight content of the FSiPA emulsion was 25%, TEOS, MTES, C ₂ H ₅ OH The ratio of the amount of the substance to NH ₃ ·H ₂ O is 1:7:60:15. At room temperature, the mixture was stirred at 300 r/min. After 6.5 hours, a hybrid emulsion was obtained. The emulsion was sprayed on the surface of a clean, dry glass substrate, and the distance between the nozzle of the spray gun and the substrate was kept at 25 cm. After drying for 36 h, a superhydrophobic coating having a self-cleaning effect can be obtained on the surface of the glass substrate after the surface is completely dried.

Example 7

Quantitative FSiPA emulsion, TEOS, MTES, C ₂ H ₅ OH and NH ₃ ·H ₂ O were added to a three-necked flask to obtain a mixed solution. The weight content of the FSiPA emulsion was 0, TEOS, MTES, C ₂ H ₅ OH and The ratio of the amount of the substance of NH ₃ ·H ₂ O is 1:5:50:10. At room temperature, the mixture was stirred at 300 r/min. After 6.5 hours, a hybrid emulsion was obtained. The emulsion was sprayed on the surface of a clean, dry glass substrate, and the distance between the nozzle of the spray gun and the substrate was kept at 25 cm. After drying for 36 h, a hydrophobic coating having a self-cleaning effect can be obtained on the surface of the glass substrate after the surface is completely dried.

In the above embodiment, Example 7 is taken as a comparative example, and other embodiments are all parallel examples. The contact angle of the hydrophobic coating obtained in the above Examples 1-7 was measured, and the contact angle of the coating was measured by a contact angle tester, and the test sample was fixed on the horizontal sample table using a double-sided tape, using a micro sampler. A water droplet having a volume of 5 μL was dropped on the surface of the coating, and the static contact angle of the surface of the sample was measured using a contact angle tester, and the average of the contact angles at five different points on the surface of the sample was used as a measurement result. The self-cleaning effect of the coating can also be tested by toner simulated contaminants. Specifically, the toner is evenly spread on the surface of the coating to observe whether the water droplets can freely roll and whether the carbon powder on the surface of the coating can be removed by the water droplets. If possible, indicate a good self-cleaning effect.

In addition, the test sample was placed in an ultraviolet aging test chamber for the aging test, and the aging time was set to 480 h. The contact angle was measured again after the aging test was completed, and it was observed whether there was a significant detachment or cracking phenomenon.

Table 1 below shows data such as contact angles of the hydrophobic coatings obtained in Examples 1-7.

Table 1

It can be seen from Table 1 that the superhydrophobic coating prepared by the present invention has a contact angle of more than 135° and both have good self-cleaning effects. After aging for 480 h, except for the severe cracking of the coating obtained in the comparative example, the coating obtained in the other examples did not show obvious peeling or cracking, and the contact angle after aging was still above 130°, and The superhydrophobic coating prepared in Examples 1-6 of the present invention had a small change in the contact angle before and after aging, but the contact angle of the hydrophobic coating prepared in the comparative example (i.e., Example 7) before and after aging was remarkable.

It can be seen that the invention improves the self-cleaning effect and durability of the hydrophobic coating, and can be directly sprayed on the surface of the substrate without heat curing, and has the characteristics of simple manufacturing process and large-area preparation. The 5% to 25% FSiPA used in the present invention can help the coating to form a film well, thereby enhancing the durability of the coating without adversely affecting the hydrophobicity of the coating. The addition of TEOS helps to increase the roughness of the coating on the surface of the substrate, thereby increasing the hydrophobicity of the coating and achieving self-cleaning. The MTES can hydrophobically modify the SiO ₂ particles produced by TEOS hydrolysis, which helps to improve the hydrophobic properties of the coating.

The invention also provides the above-mentioned application of the super-hydrophobic coating in the fields of automobiles, building materials, lamps, glass, ceramics, stainless steel, aluminum alloy, solar photovoltaic, aerospace, but not limited to the applications in the above fields, and further, the application to the present Products that invent superhydrophobic coatings include, but are not limited to, aircraft anti-icing components, self-cleaning curtain walls, self-cleaning glass, anti-fogging glass, anti-corrosion steel, anti-fouling ceramics, self-cleaning coatings, etc., which can significantly improve the anti-fouling of materials. , anti-corrosion and anti-icing properties.

Claims

A method of preparing a superhydrophobic coating, comprising:

Adding fluorine-containing silicon polyacrylate, tetraethyl orthosilicate, methyltriethoxysilane, ethanol and ammonia to the vessel to obtain a mixed solution;

The mixed liquid reacts to obtain a hybrid emulsion;

The hybrid emulsion is sprayed on the surface of the substrate and dried to obtain the superhydrophobic coating.
The method according to claim 1, wherein the fluorine-containing silicone polyacrylate accounts for 5% to 25% by mass in the mixed liquid.
The method according to claim 1, wherein the ratio of the amount of the substance of tetraethyl orthosilicate, methyltriethoxysilane, ethanol and aqueous ammonia is 1:3-7:40-60:5-15 .
The method according to claim 3, wherein the ratio of the amounts of the substances of tetraethyl orthosilicate, methyltriethoxysilane, ethanol and aqueous ammonia is 1:5:50:10.
The method according to claim 1, wherein after the fluorine-containing silicone polyacrylate, tetraethyl orthosilicate, methyltriethoxysilane, ethanol and aqueous ammonia are added to the vessel, the method further comprises:

The mixture was stirred under the conditions of 200-400 r/min.
The method of claim 1 wherein the reaction is carried out for a period of from 5 to 7 hours.
The method of claim 1 wherein the nozzle of the spray gun used for spraying is at a distance of 15-30 cm from the substrate.
The method of claim 1 wherein said drying is drying at room temperature for 12-36 hours.
The method of claim 1 wherein said superhydrophobic coating has a thickness of from 0.1 to 0.5 mm.
The method of claim 1 wherein the substrate is a glass substrate.
A superhydrophobic coating prepared by the method of any of claims 1-10.
A glass, characterized in that the glass comprises the superhydrophobic coating of claim 11.
An anti-icing device, characterized in that the anti-icing device comprises the superhydrophobic coating according to claim 11.
A self-cleaning device comprising the superhydrophobic coating of claim 11.
The superhydrophobic coating according to claim 11 is applied in the fields of automobiles, building materials, lamps, glass, ceramics, stainless steel, aluminum alloys, solar photovoltaics, and aerospace.