Super-hydrophobic self-cleaning coating and preparation method thereof

Abstract

The invention relates to the technical field of coatings, in particular to a super-hydrophobic self-cleaning coating and a preparation method thereof. The super-hydrophobic self-cleaning coating is prepared from the following components in parts by weight: 30 to 40 parts of bisphenol A type epoxy acrylate, 5 to 10 parts of hydroxyl-terminated polyphenylene ether siloxane, 10 to 20 parts of filler, 0.1 to 1 part of diethylamine, 1 to 3 parts of a photoinitiator, 1 to 3 parts of a silane coupling agent, 40 to 50 parts of a reactive diluent, 10 to 20 parts of acetone, 0.1 to 0.5 part of a rheological agent and 0.1 to 0.5 part of a de-foaming agent. The coating formed by curing has a super-hydrophobic surface, not only provides waterproof and self-cleaning characteristics, but also is high in hardness and wide in application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a super-hydrophobic self-cleaning coating and a preparation method thereof. Background Art

[0002] Superhydrophobic surfaces have properties such as self-cleaning, anti-wetting, anti-icing, corrosion resistance, and drag reduction, and thus have broad application prospects in the textile industry, construction, military, aviation and other fields.

[0003] Due to its broad application prospects and economic value, the research on super-hydrophobic surfaces has been widely developed, and a variety of super-hydrophobic surface preparation methods have emerged, such as etching, deposition, anodization, template method, electrospinning, high-temperature thermal oxidation, etc. Developing a simple, efficient, safe, and cost-effective method to achieve super-hydrophobic surface processing is of great practical significance.

[0004] Superhydrophobic coatings are an important raw material for preparing superhydrophobic surfaces and have also been an important research direction in the field of coating technology in recent years. However, the composition of existing superhydrophobic coatings often contains fluorocarbon compounds, which have high bioaccumulation, have a great impact on the environment, are difficult to degrade, and lack environmental friendliness. Summary of the Invention

[0005] Purpose of the invention: In response to the above technical problems, the present invention proposes a super-hydrophobic self-cleaning coating and a preparation method thereof.

[0006] The technical solutions adopted are as follows: A super-hydrophobic self-cleaning coating, comprising the following components in parts by weight: 30-40 parts of bisphenol A epoxy acrylate, 5-10 parts of terminal hydroxyl polyphenylene ether siloxane, 10-20 parts of filler, 0.1-1 part of diethylamine, 1-3 parts of photoinitiator, 1-3 parts of silane coupling agent, 40-50 parts of active diluent, 10-20 parts of acetone, 0.1-0.5 parts of rheological agent, and 0.1-0.5 parts of defoaming agent.

[0007] Furthermore, the hydroxy-terminated polyphenylene ether siloxane is prepared from hydroxy silicone oil, 1,4-bis(dialkylhydroxysilyl)benzene and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether.

[0008] Furthermore, the mass ratio of the hydroxy silicone oil, 1,4-bis(dialkylhydroxysilyl)benzene and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether is 4-8:1-2:1-2.

[0009] Furthermore, the 1,4-bis(dialkylhydroxysilyl)benzene is composed of 1,4-bis(dimethylhydroxysilyl)benzene and a long-chain compound; The structure of the long-chain compound is shown below: ; Wherein, R is an alkyl group having ≥6 carbon atoms.

[0010] Furthermore, R is any one of hexyl, heptyl, octyl, nonyl, and decyl.

[0011] Furthermore, R is n-octyl.

[0012] Furthermore, the mass ratio of the 1,4-bis(dimethylhydroxysilyl)benzene to the long-chain compound is 1-5:1-5.

[0013] Furthermore, the preparation method of the hydroxy-terminated polyphenylene ether siloxane is as follows: Under nitrogen protection, mix hydroxy silicone oil, 1,4-bis(dialkylhydroxysilyl)benzene and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether, stir and heat to 60-70℃ under negative pressure to remove low boiling points, add tetramethylammonium hydroxide silicon alkoxide, then heat to 90-120℃, keep warm and react for 4-8h, then heat to 150-160℃, continue to keep warm and react for 1-3h, finally heat to 180-200℃ and remove low boiling points again under negative pressure, then return to room temperature.

[0014] Furthermore, the filler is epoxidized silica.

[0015] Furthermore, the silane coupling agent is KH-550 and / or KH-560.

[0016] Furthermore, the reactive diluent consists of butyl acrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate.

[0017] The active diluent is composed of butyl acrylate, tripropylene glycol diacrylate and trimethylolpropane triacrylate in a mass ratio of 2.5:1:1.

[0018] The present invention also provides a method for preparing a super-hydrophobic self-cleaning coating: Bisphenol A epoxy acrylate, terminal hydroxyl polyphenylene ether siloxane, filler, diethylamine, photoinitiator, silane coupling agent, active diluent, acetone, rheological agent and defoaming agent are mixed evenly.

[0019] Beneficial effects of the present invention: The present invention provides a super-hydrophobic self-cleaning coating, wherein bisphenol A epoxy acrylate is used as the base resin of the coating, and the acrylate and epoxy groups in the structure thereof give it dual reactivity, providing a flexible control means for the "low surface energy modification" and "micro-nano structure construction" of the super-hydrophobic coating, and the terminal hydroxyl polyphenylene ether siloxane has the intrinsic characteristic of low surface energy, and the terminal hydroxyl group can participate in the cross-linking and curing of the bisphenol A epoxy acrylate, thereby introducing silicon-oxygen bonds and rigid groups phenylene and phenylene ether groups into the cross-linking system, effectively improving the hardness of the coating after curing and changing the microscopic morphology of the coating surface, thereby enhancing the hydrophobicity, and making The static contact angle increases and the rolling angle decreases. Nano-silica has an extremely high specific surface area. In the coating, nanoparticles self-assemble through van der Waals forces or hydrogen bonds to form micron-sized aggregates, which together with the original nanoparticles constitute a super-hydrophobic surface with a micron-nano multi-level structure. The epoxy group can improve the dispersibility of the nano-silica and participate in the curing of the coating, avoiding the destruction of the super-hydrophobic surface caused by the excessive aggregation of the nano-silica. The super-hydrophobic self-cleaning coating of the present invention does not contain fluorocarbon compounds. The coating formed by curing has a super-hydrophobic surface, which not only provides waterproof and self-cleaning properties, but also has high hardness and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the synthesis route of the hydroxy-terminated polyphenylene ether siloxane in Example 1. DETAILED DESCRIPTION

[0021] Unless otherwise specified, the following examples and comparative examples were conducted in parallel, using the same processing steps and parameters.

[0022] Bisphenol A epoxy acrylate: Sartomer CN110 NS, purchased from Shanghai Buding Chemical Co., Ltd. Hydroxyl-terminated polyphenylene ether siloxane: homemade; Filling: Homemade; Diethylamine: purchased from Wuhan Jiyesheng Chemical Co., Ltd. Photoinitiator 651: purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd. Silane coupling agent KH-550: purchased from Shandong Rongsheng New Materials Co., Ltd. Butyl acrylate: purchased from Jinan Anqi Chemical Co., Ltd. Tripropylene glycol diacrylate: purchased from Jinan Quanxing New Materials Co., Ltd. Trimethylolpropane triacrylate: Trimethylolpropane triacrylate Acetone: purchased from Jinan Anqi Chemical Co., Ltd. Rheological agent BYK-300: purchased from Guangzhou Haoyi New Materials Technology Co., Ltd. Defoaming agent BYK-A530: purchased from Guangzhou Haoyi New Materials Technology Co., Ltd.

[0023] Example 1: A super-hydrophobic self-cleaning coating, comprising the following components in parts by weight: 35 parts of bisphenol A epoxy acrylate, 8 parts of hydroxyl-terminated polyphenylene ether siloxane, 15 parts of filler, 0.5 parts of diethylamine, 2 parts of photoinitiator 651, 2 parts of silane coupling agent KH-550, 25 parts of butyl acrylate, 10 parts of tripropylene glycol diacrylate, 10 parts of trimethylolpropane triacrylate, 15 parts of acetone, 0.4 parts of rheological agent BYK-300, and 0.3 parts of defoaming agent BYK-A530; The hydroxy-terminated polyphenylene ether siloxane is prepared from hydroxy silicone oil, 1,4-bis(dimethylhydroxysilyl)benzene, 1,4-bis(dioctylhydroxysilyl)benzene and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether in a mass ratio of 6:1:1:1.5.

[0024] The preparation method of hydroxy-terminated polyphenylene ether siloxane is as follows: Under nitrogen, add 48g of magnesium chips, 633.18g of di-n-octyldimethoxysilane, and 1500mL of tetrahydrofuran to a dry reaction flask. Weigh 235.9g of p-dibromobenzene and dissolve it in 1000mL of tetrahydrofuran. Stir the reaction flask and heat it to reflux. Add the p-dibromobenzene solution in tetrahydrofuran dropwise over 3 hours. After completion, keep the reaction warm for 2 hours. Stop the reaction system and heat it to room temperature before adding the materials, removing the residue, and distilling the filtrate under reduced pressure to remove the tetrahydrofuran to obtain the intermediate. The intermediate was added to a reaction flask, which was cooled to 0-5°C. 200 mL of a 5% phosphoric acid hydrolyzate was slowly added dropwise over 3-4 hours. After the addition was complete, the mixture was kept warm and stirred for 2 hours, then returned to room temperature and stirred for 1 hour. The reaction solution was filtered, and the resulting solid was ground into powder. The solid was continuously rinsed with deionized water until neutral, and then dried to obtain 1,4-bis(dioctylhydroxysilyl)benzene. ESI-MS (m / z) (M +): Theoretical value 619.18, measured value 619.52. Under nitrogen protection, hydroxy silicone oil, 1,4-bis(dimethylhydroxysilyl)benzene, 1,4-bis(dioctylhydroxysilyl)benzene, and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether were added to a dry reaction flask. Stirring was started and the flask was heated to 60-70°C under reduced pressure to remove low-boiling substances for 2 hours. After venting, tetramethylammonium hydroxide siliconate was added at a rate of 0.1% of the total mass of the raw materials. The temperature was then raised to 110°C and kept for 6 hours. The temperature was then raised to 160°C and kept for 3 hours. Finally, the temperature was raised to 190°C and low-boiling substances were again removed under reduced pressure for 3 hours. The mixture was then returned to room temperature.

[0025] The filler is epoxidized silica, and the preparation method is as follows: Add 10 g of nano-silica to 100 mL of toluene, ultrasonicate for 30 min, then add 20 g of silane coupling agent KH-560, heat to reflux for 10 h, terminate the reaction, vacuum filter, wash the product with anhydrous ethanol, and dry it.

[0026] The preparation method of the above-mentioned super hydrophobic self-cleaning coating is as follows: Mix bisphenol A epoxy acrylate, hydroxyl-terminated polyphenylene ether siloxane, filler, diethylamine, photoinitiator 651, silane coupling agent KH-550, butyl acrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, acetone, rheological agent BYK-300, and defoaming agent BYK-A530 at room temperature.

[0027] Example 2: A super-hydrophobic self-cleaning coating, comprising the following components in parts by weight: 40 parts of bisphenol A epoxy acrylate, 10 parts of hydroxyl-terminated polyphenylene ether siloxane, 20 parts of filler, 1 part of diethylamine, 3 parts of photoinitiator 651, 3 parts of silane coupling agent KH-550, 25 parts of butyl acrylate, 10 parts of tripropylene glycol diacrylate, 10 parts of trimethylolpropane triacrylate, 20 parts of acetone, 0.5 parts of rheological agent BYK-300, and 0.5 parts of defoaming agent BYK-A530; The hydroxy-terminated polyphenylene ether siloxane is prepared from hydroxy silicone oil, 1,4-bis(dimethylhydroxysilyl)benzene, 1,4-bis(dioctylhydroxysilyl)benzene and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether in a mass ratio of 8:1:1:2. The preparation method of hydroxy-terminated polyphenylene ether siloxane and filler is the same as that in Example 1.

[0028] The preparation method of the above-mentioned super hydrophobic self-cleaning coating is as follows: Mix bisphenol A epoxy acrylate, hydroxyl-terminated polyphenylene ether siloxane, filler, diethylamine, photoinitiator 651, silane coupling agent KH-550, butyl acrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, acetone, rheological agent BYK-300, and defoaming agent BYK-A530 at room temperature.

[0029] Example 3: A super-hydrophobic self-cleaning coating, comprising the following components in parts by weight: 30 parts of bisphenol A epoxy acrylate, 5 parts of hydroxyl-terminated polyphenylene ether siloxane, 10 parts of filler, 0.1 parts of diethylamine, 1 part of photoinitiator 651, 1 part of silane coupling agent KH-550, 25 parts of butyl acrylate, 10 parts of tripropylene glycol diacrylate, 10 parts of trimethylolpropane triacrylate, 10 parts of acetone, 0.1 parts of rheological agent BYK-300, and 0.1 parts of defoaming agent BYK-A530; The hydroxy-terminated polyphenylene ether siloxane is prepared from hydroxy silicone oil, 1,4-bis(dimethylhydroxysilyl)benzene, 1,4-bis(dioctylhydroxysilyl)benzene and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether in a mass ratio of 4:1:1:1. The preparation method of hydroxy-terminated polyphenylene ether siloxane and filler is the same as that in Example 1.

[0030] The preparation method of the above-mentioned super hydrophobic self-cleaning coating is as follows: Mix bisphenol A epoxy acrylate, hydroxyl-terminated polyphenylene ether siloxane, filler, diethylamine, photoinitiator 651, silane coupling agent KH-550, butyl acrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, acetone, rheological agent BYK-300, and defoaming agent BYK-A530 at room temperature.

[0031] Example 4: A super-hydrophobic self-cleaning coating, comprising the following components in parts by weight: 40 parts of bisphenol A epoxy acrylate, 5 parts of hydroxyl-terminated polyphenylene ether siloxane, 20 parts of filler, 0.1 parts of diethylamine, 3 parts of photoinitiator 651, 1 part of silane coupling agent KH-550, 25 parts of butyl acrylate, 10 parts of tripropylene glycol diacrylate, 10 parts of trimethylolpropane triacrylate, 20 parts of acetone, 0.1 parts of rheological agent BYK-300, and 0.1 parts of defoaming agent BYK-A530; The hydroxy-terminated polyphenylene ether siloxane is prepared from hydroxy silicone oil, 1,4-bis(dimethylhydroxysilyl)benzene, 1,4-bis(dioctylhydroxysilyl)benzene and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether in a mass ratio of 4:1:1:2. The preparation method of hydroxy-terminated polyphenylene ether siloxane and filler is the same as that in Example 1.

[0032] The preparation method of the above-mentioned super hydrophobic self-cleaning coating is as follows: Mix bisphenol A epoxy acrylate, hydroxyl-terminated polyphenylene ether siloxane, filler, diethylamine, photoinitiator 651, silane coupling agent KH-550, butyl acrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, acetone, rheological agent BYK-300, and defoaming agent BYK-A530 at room temperature.

[0033] Comparative Example 1: The process is basically the same as Example 1, except that no hydroxyl-terminated polyphenylene ether siloxane is added.

[0034] Comparative Example 2: The method is basically the same as Example 1, except that 1,4-bis(dioctylhydroxysilyl)benzene is not added during the preparation of the hydroxy-terminated polyphenylene ether siloxane.

[0035] Comparative Example 3: The method is basically the same as Example 1, except that 4,4'-bis(dimethylhydroxysilyl)diphenyl ether is not added during the preparation of the hydroxy-terminated polyphenylene ether siloxane.

[0036] Comparative Example 4: The method is basically the same as Example 1, except that nano-silica is directly used as the filler, that is, it is not subjected to epoxidation modification treatment.

[0037] Performance testing: The glass slide was washed repeatedly with deionized water and anhydrous ethanol several times and dried in a drying oven. The superhydrophobic self-cleaning coatings of Examples 1-4 and Comparative Examples 1-4 were respectively coated on a glass slide using a wire rod applicator and placed in an ultraviolet irradiation machine for curing at a power of 1000 W, a distance of 15 cm between the glass slide and the UV lamp, a temperature of 39°C in the curing box, and a curing time of 90 seconds. The cured samples were placed in a desiccator for later use.

[0038] The static contact angle of the droplet on the sample surface was measured using the SDC-100 optical contact angle meter by the sessile drop method, and the rolling angle of the droplet just rolling down on the coating surface was measured using the GFSG60-35 manual angle stage.

[0039] The hardness of the sample coating was measured using a QHQ-A pencil scratch hardness tester according to the national standard GB / T 6739-2006.

[0040] The test results are shown in Table 1 below: As can be seen from Table 1 above, the coating formed by curing the super-hydrophobic self-cleaning coating of the present invention has a super-hydrophobic surface, which not only provides waterproof and self-cleaning properties, but also has high hardness and broad application prospects.

[0041] By comparing Example 1 with Comparative Example 1, it can be seen that the addition of hydroxy-terminated polyphenylene ether siloxane helps to improve the superhydrophobicity and hardness of the coating.

[0042] By comparing Example 1 and Comparative Example 2, it can be seen that the addition of 1,4-bis(dioctylhydroxysilyl)benzene during the preparation of terminal hydroxy polyphenylene ether siloxane helps to improve the superhydrophobic properties and hardness of the coating. The reason may be that the introduction of long alkyl chains and rigid phenylene groups with lower surface energy weakens the interaction between water molecules and the coating surface, thereby increasing the static contact angle and decreasing the rolling angle.

[0043] By comparing Example 1 and Comparative Example 3, it can be seen that the addition of 4,4'-bis(dimethylhydroxysilyl)diphenyl ether in the preparation of terminal hydroxy polyphenylene ether siloxane helps to improve the superhydrophobicity and hardness of the coating. The reason may be that the rigid group of the phenylene ether group can "support" the long alkyl chain, reduce the curling of the long alkyl chain, increase the surface alkyl density, thereby reducing the surface energy, and affecting the film-forming process of the coating, thereby changing the micromorphology of the coating surface, forming a rough structure to enhance the hydrophobicity.

[0044] By comparing Example 1 and Comparative Example 4, it can be seen that the epoxy group modified on the filler surface helps to improve the superhydrophobicity and hardness of the coating. The reason may be that the epoxy group can improve the dispersibility of the filler and participate in the curing of the coating, thereby promoting the formation of a high-roughness superhydrophobic surface.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A super hydrophobic self-cleaning coating, characterized in that, It is composed of the following ingredients in parts by weight: 30-40 parts of bisphenol A epoxy acrylate, 5-10 parts of terminal hydroxyl polyphenylene ether siloxane, 10-20 parts of filler, 0.1-1 part of diethylamine, 1-3 parts of photoinitiator, 1-3 parts of silane coupling agent, 40-50 parts of active diluent, 10-20 parts of acetone, 0.1-0.5 parts of rheological agent, and 0.1-0.5 parts of defoaming agent.

2. The super hydrophobic self-cleaning coating according to claim 1, wherein The hydroxy-terminated polyphenylene ether siloxane is prepared from hydroxy silicone oil, 1,4-bis(dialkylhydroxysilyl)benzene and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether.

3. The super hydrophobic self-cleaning coating according to claim 2, wherein The mass ratio of the hydroxy silicone oil, 1,4-bis(dialkylhydroxysilyl)benzene and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether is 4-8:1-2:1-2.

4. The super hydrophobic self-cleaning coating according to claim 2, wherein The 1,4-bis(dialkylhydroxysilyl)benzene is composed of 1,4-bis(dimethylhydroxysilyl)benzene and a long-chain compound; The structure of the long-chain compound is shown below: ； Wherein, R is an alkyl group having ≥6 carbon atoms.

5. The super hydrophobic self-cleaning coating according to claim 4, wherein The mass ratio of the 1,4-bis(dimethylhydroxysilyl)benzene to the long-chain compound is 1-5:1-5.

6. The super hydrophobic self-cleaning coating according to claim 2, wherein The preparation method of the hydroxy-terminated polyphenylene ether siloxane is as follows: Under nitrogen protection, mix hydroxy silicone oil, 1,4-bis(dialkylhydroxysilyl)benzene and 4,4'-bis(dimethylhydroxysilyl)diphenyl ether, stir and heat to 60-70℃ under negative pressure to remove low boiling points, add tetramethylammonium hydroxide silicon alkoxide, then heat to 90-120℃, keep warm and react for 4-8h, then heat to 150-160℃, continue to keep warm and react for 1-3h, finally heat to 180-200℃ and remove low boiling points again under negative pressure, then return to room temperature.

7. The super hydrophobic self-cleaning coating according to claim 1, wherein The filler is epoxidized silica.

8. The super hydrophobic self-cleaning coating according to claim 1, wherein The silane coupling agent is KH-550 and / or KH-560.

9. The super hydrophobic self-cleaning coating according to claim 1, wherein The active diluent consists of butyl acrylate, tripropylene glycol diacrylate and trimethylolpropane triacrylate.

10. A method for preparing a super hydrophobic self-cleaning coating according to any one of claims 1 to 9, characterized in that: The details are as follows: Bisphenol A epoxy acrylate, terminal hydroxyl polyphenylene ether siloxane, filler, diethylamine, photoinitiator, silane coupling agent, active diluent, acetone, rheological agent and defoaming agent are mixed evenly.

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