Hydrophobic and oleophobic ultrathin display screen antifouling coating and preparation process thereof

Abstract

The invention provides a hydrophobic and oleophobic ultrathin display screen antifouling coating and a preparation process thereof, and the preparation process comprises the following steps: mixing epoxy resin or polyacrylic resin and an amino curing agent in an organic solvent, uniformly stirring, and spraying on a display screen substrate to form a resin substrate; the preparation method comprises the following steps: mixing tetraethyl orthosilicate, fluorine-containing organosilane and nanoparticles in an organic solvent, and uniformly stirring to obtain a first nanoparticle solution; mixing fluorine-containing organosilane and nanoparticles in an organic solvent, and uniformly stirring to obtain a second nanoparticle solution; mixing the first nanoparticle solution, the second nanoparticle solution and a silane coupling agent, and uniformly stirring to obtain a hydrophobic and oleophobic solution; and curing the hydrophobic and oleophobic solution on a resin substrate to obtain the hydrophobic and oleophobic ultrathin display screen antifouling coating. The preparation process is simple, and the prepared coating has excellent hydrophobic and oleophobic performance and stability.

Description

Technical Field

[0001] The invention belongs to the technical field of coating preparation, and in particular relates to a hydrophobic and oleophobic ultra-thin display screen antifouling coating and a preparation process thereof. Background Art

[0002] With the development of science and technology and people's increasing requirements for product performance, a single hydrophobic coating can no longer meet people's actual needs, and super-hydrophobic and oleophobic coating materials are receiving more and more attention.

[0003] With the help of microchemistry, various hydrophobic and oleophobic coating materials and preparation processes have emerged. In the existing hydrophobic and oleophobic coating preparation processes, the core components are nothing more than hydrophobic and oleophobic components that provide hydrophobic and oleophobic properties, and components that provide adhesion to the substrate (mostly resins). The preparation methods involve electrochemical etching, electrodeposition, template method, etc. To ensure the hydrophobicity, oleophobicity and stability of the coating, the existing technologies involve the following preparation technologies: The coating is prepared by in-situ reaction of organosilicon and nanoparticles. However, this method is cumbersome to prepare, and the excessive filler content will affect the transparency of the coating. The coating is formed by mixing organic silicon, organic ammonia and resin in a solvent and then curing it at high temperature. However, the high temperature curing process has high requirements on the substrate and is not conducive to its use on heat-sensitive substrates. By hydrolyzing and polycondensing siloxane monomers, a coating with excellent hydrophobicity and high-temperature resistance is obtained, but this coating has poor wear resistance.

[0004] In summary, among the existing coating preparation technologies, there are few that focus on hydrophobicity, oleophobicity, friction resistance, high temperature resistance and preparation convenience. Summary of the Invention

[0005] The purpose of the present invention is to provide a hydrophobic and oleophobic ultra-thin display antifouling coating and a preparation process thereof, so as to solve the problems of poor stability and complicated preparation in the existing hydrophobic and oleophobic coating preparation process, and to provide a hydrophobic and oleophobic ultra-thin display antifouling coating and a preparation process thereof with good stability, good hydrophobic and oleophobic effect and convenient preparation.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A process for preparing a hydrophobic and oleophobic ultra-thin display antifouling coating comprises the following steps: Step S1: mixing epoxy resin or polyacrylic resin and amino curing agent in an organic solvent, stirring evenly and then spraying on a display screen substrate to form a resin substrate; Step S2: mixing tetraethyl orthosilicate, fluorinated organosilane, and nanoparticles in an organic solvent, and stirring to obtain a first nanoparticle solution; Step S3: mixing the fluorinated organosilane and the nanoparticles in an organic solvent and stirring to obtain a second nanoparticle solution; Step S4: mixing the first nanoparticle solution, the second nanoparticle solution and the silane coupling agent, and stirring them to obtain a hydrophobic and oleophobic solution; Step S5: curing the hydrophobic and oleophobic solution on the resin substrate to obtain a hydrophobic and oleophobic ultra-thin display screen antifouling coating.

[0007] Wherein, in the step S1, The epoxy resin is selected from any one of bisphenol A epoxy resin, bisphenol F epoxy resin or glycidyl ester; The amine curing agent is selected from any one of diethylaminoethanol, diethylaminomethyltriethoxysilane, dicyandiamide or diphenyldisulfide; The mass ratio of epoxy resin or polyacrylic resin to amino curing agent and organic solvent is (10-20):1:(10-20).

[0008] Wherein, in the step S2, The fluorinated organosilane is selected from fluorinated octyltrichlorosilane or fluorinated octyldimethylmethoxysilane; The nanoparticles are selected from nano zinc oxide particles or nano tin oxide particles; The mass ratio of tetraethyl orthosilicate, fluorinated organosilane, nanoparticles and organic solvent is: (4-6): (3-4): 1: (55-65).

[0009] Wherein, in said step S3, The fluorine-containing organosilane is selected from any one of heptadecafluorodecyltriethoxysilane, perfluorooctyltriethoxysilane or perfluorodecyltrichlorosilane; The nanoparticles are selected from nano zinc oxide particles or nano tin oxide particles; The mass ratio of fluorinated organosilane, nanoparticles and organic solvent is: (5-6):1:(55-65).

[0010] Wherein, in said step S4, The silane coupling agent is selected from any one of γ-glycidyloxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, γ-(2,3-epoxypropyloxy)propyltrimethoxysilane or 3-aminopropyltriethoxysilane; The mass ratio of the first nanoparticle solution, the second nanoparticle solution and the silane coupling agent is: (15-20): (15-20): 1.

[0011] Wherein, the particle size of the nanoparticles in step S2 is 80-100 nm; The particle size of the nanoparticles in step S3 is 40-60 nm.

[0012] Wherein, the organic solvent in step S1 is selected from any one of acetone, ethanol, ethyl acetate, toluene, diethyl ether or xylene; The organic solvent in step S2 is selected from any one of methanol, ethanol, ethyl acetate, toluene, diethyl ether or n-butanol; The organic solvent in step S3 is selected from any one of methanol, ethanol, ethyl acetate, toluene, diethyl ether or n-butanol.

[0013] Wherein, in the step S5, the curing method is: using a spray gun to spray the hydrophobic and oleophobic solution onto the resin substrate at a pressure of 500-600 kPa for 1-2 minutes, and curing by vacuum ultraviolet method.

[0014] A hydrophobic and oleophobic ultra-thin display screen antifouling coating is prepared by any of the above-mentioned preparation processes.

[0015] The antifouling coating comprises a display screen substrate, a resin substrate and an antifouling coating, wherein the thickness of the resin substrate is 20-40 nm, and the thickness of the antifouling coating is 100-120 nm.

[0016] Compared with the prior art, the advantages and beneficial effects of the present invention are: 1. In the process of forming the resin base, the present invention attempts to improve the bonding stability between the resin, the display screen base, and the hydrophobic and oleophobic coating by adding a curing agent. It has been verified that by introducing an amine-based curing agent into the epoxy resin or polyacrylic resin, the bonding stability of the epoxy resin or polyacrylic resin and the display screen base can be improved. At the same time, the amine-based curing agent increases the connectivity between the subsequently formed hydrophobic and oleophobic coating and the resin component in the resin base, ensuring the stability of the hydrophobic and oleophobic coating in the event of friction damage and high temperature damage, so that the final coating can continue to maintain excellent hydrophobic and oleophobic properties. 2. To achieve a coating with excellent hydrophobic and oleophobic properties, the present invention attempts to provide nanoparticle solutions with varying surface energies, in order to form a multi-layered micro-nanostructure. The inventors explored methods for maximizing surface energy variation from multiple perspectives, including modification mechanism, nanoparticle size, nanoparticle solution ratio, and other additives. Ultimately, they selected nanoparticle solutions that offer varying surface energies through different modification mechanisms and particle sizes. Specifically, in the first nanoparticle solution, tetraethyl orthosilicate and fluorinated organic silane are reacted to generate silica coating the nanoparticles, ensuring that the first nanoparticles and the second nanoparticles are staggered in distribution, which is beneficial to the orderly distribution of the nanoparticles in the subsequent solution; while in the second nanoparticle solution, the nanoparticles are directly modified by fluorinated organic silane to obtain nanoparticles modified by fluorinated organic silane; and the first nanoparticles are larger than the second nanoparticles; in the process of mixing the first nanoparticle solution and the second nanoparticle solution, the first nanoparticles are deposited downward, so that more first nanoparticles are distributed near the resin substrate, and the silica coating on the first nanoparticles is cross-linked with the amino-based curing agent in the resin substrate, ensuring the stable bonding of the hydrophobic and oleophobic coating on the resin substrate; the orderly distribution of the second nanoparticles and the first nanoparticles is beneficial to the formation of a multi-level micro-nano structure, thereby improving the hydrophobic and oleophobic properties; 3. In order to ensure the orderly and stable distribution of the first nanoparticles and the second nanoparticles and avoid the first nanoparticles from settling at an excessively fast rate during the mixing process, the present invention further introduces a silane coupling agent during the mixing process of the first nanoparticle solution and the second nanoparticle solution, and screens four preferred components of the silane coupling agent. The silane coupling agent can improve the compatibility of the first nanoparticle solution and the second nanoparticle solution, ensure the uniformity of dispersion of the first nanoparticle solution and the second nanoparticle solution, and avoid the second nanoparticles from agglomerating with the silica coated on the surface of the first nanoparticles during the fluorination process. DETAILED DESCRIPTION

[0017] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0018] Example 1: Step S1: 15 g of bisphenol A epoxy resin and 1 g of diethylaminomethyltriethoxysilane were dissolved in 20 g of acetone (about 25 mL). After stirring evenly, the mixture was sprayed onto the display substrate using a spray gun to form a resin substrate. The spraying time was 1 minute and the spray gun pressure was 600 kPa. Step S2: 6 g of tetraethyl orthosilicate, 4 g of fluorinated octyltrichlorosilane, and 1 g of nano-zinc particles (particle size 80 nm) were dissolved in 60 g of ether (about 85 mL), and stirred to obtain a first nano-particle solution; Step S3: 6 g of heptadecafluorodecyltriethoxysilane and 1 g of nano-zinc particles (particle size 40 nm) were dissolved in 60 g of ether (about 85 mL), and stirred to obtain a second nano-particle solution; Step S4: Take 20 g of the first nanoparticle solution (about 18 mL) and 20 g of the second nanoparticle solution (about 18 mL), add 1 g of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, and stir evenly to obtain a hydrophobic and oleophobic solution; Step S5: Curing the hydrophobic and oleophobic solution on the resin substrate to obtain a hydrophobic and oleophobic ultrathin display antifouling coating, the curing step includes: spraying with a spray gun, and then curing with ultraviolet light, the spray gun pressure is 600 kPa, the spraying time is 1 minute, the ultraviolet light source is 150 nm, the oxygen content is 6%, and the curing time is 60 minutes.

[0019] The operating steps of Examples 2-9 are similar to those of Example 1, except for the selection of specific operating parameters. The specific operating parameters of Examples 2-9 are shown in Tables 1 to 5.

[0020] Table 1: Operating parameters of step S1 of Example 2-Example 9

[0021] Table 2: Operating parameters of step S2 of Example 2-Example 9

[0022] Table 3: Operating parameters of step S3 of Example 2-Example 9

[0023] Table 4: Operating parameters of step S4 of Example 2-Example 9

[0024] Table 5: Operating parameters of step S5 of Example 2-Example 9

[0025] Comparative Example 1: The difference from Example 1 is that the amino curing agent - diethylaminomethyltriethoxysilane is not added in step S1, and the remaining steps are the same as those in the example.

[0026] Comparative Example 2: The difference from Example 1 is that step S2 and step S4 are omitted, that is, the preparation of the first particle solution is omitted. Correspondingly, the mixing operation of the first particle solution and the second particle solution is omitted. The remaining steps are the same as Example 1.

[0027] Comparative Example 3: The difference from Example 1 is that step S3 and step S4 are omitted, that is, the preparation of the second particle solution is omitted. Correspondingly, the mixing operation of the first particle solution and the second particle solution is omitted. The remaining steps are the same as Example 1.

[0028] Comparative Example 4: The difference from Example 1 is that the silane coupling agent -γ-(2,3-epoxypropoxy)propyltrimethoxysilane is not added in step S4, and the remaining steps are the same as those in Example 1.

[0029] Comparative Example 5: The difference from Example 1 is that tetraethyl orthosilicate and fluorinated organosilane - fluorinated octyltrichlorosilane are not added in step S2, and the remaining steps are the same as in Example 1.

[0030] Comparative Example 6: The difference from Example 1 is that the fluorine-containing organic silane - heptadecafluorodecyltriethoxysilane is not added in step S3, and the remaining steps are the same as in Example 1.

[0031] In the above-mentioned Examples 1 to 9 and Comparative Examples 1 to 6 of the present invention, some of the preparations involved are from the following sources: Amine curing agents: diethylaminoethanol was purchased from Jinan Xinchen Chemical Co., Ltd., diethylaminomethyltriethoxysilane, dicyandiamide and diphenyldisulfide were purchased from Jiangsu Pules Biotechnology Co., Ltd. Epoxy resins: bisphenol A epoxy resin, bisphenol F epoxy resin and glycidyl ester were purchased from Jinan Haowen Chemical Co., Ltd. The viscosity of bisphenol A epoxy resin is 20,000-30,000, and the viscosity of bisphenol F epoxy resin is 10,000-20,000; Polyacrylic acid resin: purchased from Mitsui Chemicals, product model GMAAlmatex PD7610, molecular weight 200-500; Fluorinated organosilanes: Fluorinated octyltrichlorosilane, fluorinated octyldimethylmethoxysilane, heptadecafluorodecyltriethoxysilane, perfluorooctyltriethoxysilane, and perfluorodecyltrichlorosilane were purchased from Mitsui Chemicals. Nanoparticles: Nano zinc oxide and nano tin oxide were purchased from Mitsui Chemicals; Silane coupling agents: γ-glycidyloxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, and γ-(2,3-epoxypropyloxy)propyltrimethoxysilane were purchased from Shanghai Yuanye Biotechnology Co., Ltd., and 3-aminopropyltriethoxysilane was purchased from Merck’s official website.

[0032] For the coatings prepared in Examples 1 to 9 and Comparative Examples 1 to 6, the hydrophobicity and oleophobicity results were verified, as shown in Table 1; wherein, the contact angle was measured by a contact angle analyzer DSA100E; the rolling angle was measured by dropping 1 mL of an organic solution or water to the coating interface and observing the inclination angle of the coating when the water or organic solution began to slide off. The organic solutions were n-hexadecane, ethanol, and methanol. In Table 1, the oil rolling angle is the average rolling angle of the coating for n-hexadecane, ethanol, and methanol. The rolling angles in Tables 2 and 3 below have the same meaning.

[0033] Table 1: Hydrophobic and oleophobic experimental data of Examples 1 to 9 and Comparative Examples 1 to 6

[0034] The coating was placed at a high temperature of 250 degrees Celsius for 24 hours. Afterwards, the water contact angle, water sliding angle, oil contact angle, and oil sliding angle were measured again. The results are shown in Table 2.

[0035] Table 2: Hydrophobic and oleophobic experimental data of high temperature damage experiments Examples 1 to 9 and Comparative Examples 1 to 6

[0036] The coating was rubbed on a TABER friction machine (TEST Instruments, Germany) at a friction revolution of 500 and a load of 1 N. Afterwards, the water contact angle, water rolling angle, oil contact angle, and oil rolling angle were measured again. The results are shown in Table 3.

[0037] Table 3: Friction damage test data of hydrophobic and oleophobic examples 1 to 9 and comparative examples 1 to 6

[0038] Combining the data of Examples 1 to 9 in Tables 1-3, it can be seen that the present invention provides a coating material with super hydrophobic and oleophobic properties by introducing an amino curing agent, nanoparticles with different surface energies, and a silane coupling agent, and after high temperature damage and friction damage, it can still maintain excellent hydrophobic and oleophobic properties; Combining the data of Example 1 and Comparative Example 1, it can be seen that without adding an amino curing agent, although the prepared coating also has good hydrophobic and oleophobic properties, due to the lack of cross-linking between the amino curing agent and the hydrophobic and oleophobic layer, the stability of this performance is extremely poor, and the performance rapidly declines under friction or high temperature conditions. Combined with the data of Example 1 and Comparative Examples 2 and 3, it can be seen that: when the first particle solution or the second particle solution is omitted, since nanoparticles with different surface energies cannot be provided in the solution system, a multi-level micro-nano structure cannot be formed, which directly leads to a significant decrease in the hydrophobic and oleophobic properties; Combined with the data of Example 1 and Comparative Examples 4 to 6, it can be seen that: when there is a lack of a silane coupling agent, a lack of silica-coated first nanoparticles, or no fluoroorganic silane modification of the second nanoparticles, the order and stable distribution of the first nanoparticles and the second nanoparticles in the hydrophobic and oleophobic coating will be affected, thereby affecting the hydrophobic and oleophobic properties.

[0039] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A process for preparing a hydrophobic and oleophobic ultra-thin display antifouling coating, characterized in that The steps include: Step S1: mixing epoxy resin or polyacrylic resin and amino curing agent in an organic solvent, stirring evenly and then spraying on a display screen substrate to form a resin substrate; Step S2: mixing tetraethyl orthosilicate, fluorinated organosilane, and nanoparticles in an organic solvent, and stirring to obtain a first nanoparticle solution; Step S3: mixing the fluorinated organosilane and the nanoparticles in an organic solvent and stirring to obtain a second nanoparticle solution; Step S4: mixing the first nanoparticle solution, the second nanoparticle solution and the silane coupling agent, and stirring them to obtain a hydrophobic and oleophobic solution; Step S5: curing the hydrophobic and oleophobic solution on the resin substrate to obtain a hydrophobic and oleophobic ultra-thin display screen antifouling coating.

2. The process for preparing the hydrophobic and oleophobic ultra-thin display antifouling coating according to claim 1, characterized in that: In the step S1, The epoxy resin is selected from any one of bisphenol A epoxy resin, bisphenol F epoxy resin or glycidyl ester; The amine curing agent is selected from any one of diethylaminoethanol, diethylaminomethyltriethoxysilane, dicyandiamide or diphenyldisulfide; The mass ratio of epoxy resin or polyacrylic resin to amino curing agent and organic solvent is (10-20):1:(10-20).

3. The process for preparing the hydrophobic and oleophobic ultra-thin display antifouling coating according to claim 1, characterized in that: In the step S2, The fluorinated organosilane is selected from fluorinated octyltrichlorosilane or fluorinated octyldimethylmethoxysilane; The nanoparticles are selected from nano zinc oxide particles or nano tin oxide particles; The mass ratio of tetraethyl orthosilicate, fluorinated organosilane, nanoparticles and organic solvent is: (4-6): (3-4): 1: (55-65).

4. The process for preparing the hydrophobic and oleophobic ultra-thin display antifouling coating according to claim 1, characterized in that: In the step S3, The fluorine-containing organosilane is selected from any one of heptadecafluorodecyltriethoxysilane, perfluorooctyltriethoxysilane or perfluorodecyltrichlorosilane; The nanoparticles are selected from nano zinc oxide particles or nano tin oxide particles; The mass ratio of fluorinated organosilane, nanoparticles and organic solvent is: (5-6):1:(55-65).

5. The process for preparing the hydrophobic and oleophobic ultra-thin display antifouling coating according to claim 1, characterized in that: In the step S4, The silane coupling agent is selected from any one of γ-glycidyloxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, γ-(2,3-epoxypropyloxy)propyltrimethoxysilane or 3-aminopropyltriethoxysilane; The mass ratio of the first nanoparticle solution, the second nanoparticle solution and the silane coupling agent is: (15-20): (15-20):

1.

6. The process for preparing a hydrophobic and oleophobic ultra-thin display antifouling coating according to claim 1, characterized in that: The particle size of the nanoparticles in step S2 is 80-100 nm; The particle size of the nanoparticles in step S3 is 40-60 nm.

7. The process for preparing a hydrophobic and oleophobic ultra-thin display antifouling coating according to claim 1, characterized in that: The organic solvent in step S1 is selected from any one of acetone, ethanol, ethyl acetate, toluene, diethyl ether or xylene; The organic solvent in step S2 is selected from any one of methanol, ethanol, ethyl acetate, toluene, diethyl ether or n-butanol; The organic solvent in step S3 is selected from any one of methanol, ethanol, ethyl acetate, toluene, diethyl ether or n-butanol.

8. The process for preparing a hydrophobic and oleophobic ultra-thin display screen antifouling coating according to claim 1, characterized in that: In step S5, the curing method is: using a spray gun to spray the hydrophobic and oleophobic solution onto the resin substrate at a pressure of 500-600 kPa for 1-2 minutes, and curing by vacuum ultraviolet method.

9. A hydrophobic and oleophobic ultra-thin display screen antifouling coating, characterized by: It is prepared by the preparation process according to any one of claims 1 to 8.

10. The hydrophobic and oleophobic ultra-thin display screen antifouling coating according to claim 9, characterized in that: The antifouling coating comprises a display screen substrate, a resin substrate and an antifouling coating, wherein the thickness of the resin substrate is 20-40 nm, and the thickness of the antifouling coating is 100-120 nm.

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