WO2019080287A1

WO2019080287A1 - Transparent hydrophobic wear-resistant coating and preparation method therefor

Info

Publication number: WO2019080287A1
Application number: PCT/CN2017/115801
Authority: WO
Inventors: 孙大陟; 雷凡; 吴冰羽
Original assignee: 南方科技大学
Priority date: 2017-10-24
Filing date: 2017-12-13
Publication date: 2019-05-02
Also published as: CN107603415B; CN107603415A

Abstract

A transparent hydrophobic wear-resistant coating and a preparation method therefor. The transparent hydrophobic wear-resistant coating is composed of an epoxy resin layer and a low-surface-energy fluorine-containing layer which are arranged in sequence from top to bottom. The preparation method therefor comprises: (1) blending epoxy resin and a curing agent into an organic solvent, and carrying out ultrasonic treatment to obtain a coating solution, the total content of the epoxy resin and the curing agent being 0.001-5wt%; by adopting a dip-coating method for a substrate material, uniformly adhering the coating solution to the surface of the substrate material, and taking out and curing to obtain the epoxy resin layer; and (2) preparing the low-surface-energy fluorine-containing layer: coating the epoxy resin layer with the fluorine-containing solution, and drying to obtain the transparent hydrophobic wear-resistant coating. The coating is equivalent to glass in transparency, the surface contact angle is 102° or above, and the hydrophobicity of the coating is controllable; the coating has excellent mechanical strength and bonding property and is convenient for large-scale industrial production.

Description

Transparent hydrophobic wear-resistant coating and preparation method thereof

Technical field

The present application relates to the field of hydrophobic materials, and in particular to a transparent hydrophobic wear-resistant coating and a preparation method thereof.

Background technique

Due to its low surface free energy, the transparent hydrophobic wear-resistant coating material has many excellent surface properties, such as antifouling property, self-cleaning property, hydrophobic oleophobicity, scratch resistance, etc., and has potential application value in many fields. . For example, windshield self-cleaning glass for spacecraft such as automobiles and airplanes can quickly condense rainwater into water droplets on the surface of the glass, take away the dirt on the surface of the glass, and also protect the glass; the curtain wall and window glass of the building, It can avoid the danger of cleaning the glass at high altitude and reduce the number of cleanings. Therefore, the transparent hydrophobic wear-resistant coating has broad application prospects in the fields of windshield, architectural glass and curtain wall, optical instruments, biomedical materials and the like.

At present, there are two main methods for preparing a transparent hydrophobic wear-resistant coating surface: one is to construct a microscopic rough surface on the surface of the hydrophobic material itself; the other is to apply a rough surface and modify the low surface energy substance. At present, constructing a suitable microscopic surface topography and ensuring that the microscopic surface topography does not affect the light transmission properties of the material surface is a key factor that restricts the wide application of transparent hydrophobic wear resistant coatings. The preparation methods of the transparent hydrophobic wear-resistant coating mainly include a bottom-up method and a top-down method.

The bottom-up method mainly includes an electrospinning method, a sol-gel method, a chemical vapor deposition method, a layer self-assembly method, and the like. Among them, the sol-gel method is widely used because it does not require complicated equipment and is easy to operate. The surface microstructure can also be controlled by controlling the hydrolysis-condensation reaction of the chemical precursor in the reaction process, thereby obtaining the corresponding rough micro-nano structure surface, so that the hydrophilicity and hydrophobicity of the coating can be controlled, and it can be widely used in silicon wafer, glass and metal. And a variety of substrate surfaces such as textile fabrics to form a hydrophobic coating. For example, Budunoglu et al. The modified silica aerogel film was prepared by the sol-gel method, and the contact angle was as high as 179°, the sliding angle was lower than 5°, and the transmittance of visible light was 87.6%. However, the preparation period of the sol-gel method is long, generally takes several days or several weeks, and the preparation efficiency of the hydrophobic coating is greatly reduced.

The top-down method mainly includes a plasma processing method, a template method, an etching method, etc., wherein the etching method has high precision, mature technology, and mass production. Can be divided into the following types: laser etching, electrochemical etching, ion etching, alkaline solution etching and acid solution etching. The main purpose is to etch the surface of the material into a nano or micron roughness structure, and then modify it with a low surface energy material to prepare a hydrophobic coating. For example, the surface of the polydimethylsiloxane is etched by laser to construct a rough microscopic morphology to make the coating hydrophobic. The disadvantages are complicated equipment, low processing efficiency and high requirements on the processing environment.

CN103436138A discloses a hybridization of nano particles and epoxy resin to obtain an epoxy resin hybrid solution, and then adding a fluorine-containing substance and a catalyst to form a fluorine-containing solution, first spraying a hybrid solution on the substrate and then spraying the fluorine-containing solution. The role of the nanoparticles is still to construct a rough surface, without the principle of the above conventional methods, and should also have the problem of reduced light transmission performance of the coated surface, and the dispersibility is difficult to control, the process is complicated, and the ultra-thin coating cannot be prepared. And the cost of nanoparticles is high, so its application is limited.

Therefore, in the existing method for preparing a transparent hydrophobic wear-resistant coating, the micro surface structure is constructed to increase the surface roughness, increase the scattering of light, generally reduce the light transmission performance of the surface of the coating, and the preparation process is complicated and the cycle is long. The conditions are harsh, and it is difficult to prepare a transparent hydrophobic wear-resistant coating on a large scale, which restricts the application of the transparent hydrophobic wear-resistant coating on glass such as mobile phones, automobiles, and spacecraft.

Summary of the invention

In view of the problems in the prior art, one of the objects of the present application is to provide a new transparent hydrophobic wear resistant coating and a method of preparing the same. Effectively improve the hydrophobic properties of plastic, metal, glass substrate materials, the coating has excellent interfacial adhesion to the substrate material, and the coating can maintain high light transmission.

In a first aspect, the present application provides a transparent hydrophobic wear resistant coating comprising an epoxy resin layer and a low surface energy fluorine-containing layer arranged in this order from top to bottom.

Further, the epoxy resin layer has a thickness of 5 nm to 5 μm, preferably 10 nm to 100 nm. The thickness of the epoxy resin layer spontaneously forms a rough microscopic rough surface during the preparation process. Unlike the prior art, the uneven microscopic rough surface is formed by a transparent epoxy thin layer, which does not affect the overall coating. The transparency of the layer, while the thickness ensures that the bonding of the epoxy layer does not decrease.

Further, the epoxy resin layer includes an epoxy resin and a curing agent.

Further, the epoxy resin includes a bisphenol A type epoxy resin and/or a bisphenol F type epoxy resin.

Further, the curing agent comprises any one or a combination of at least two of an aromatic amine, a polyether amine, an ethanolamine, an aminopropanol and an amino alcohol, wherein a typical but non-limiting combination is: an aromatic amine and a polyether amine. Combination, combination of polyetheramine and ethanolamine, combination of aminopropanol and amino alcohol, combination of ethanolamine and amino alcohol, combination of ethanolamine, aminopropanol and amino alcohol; preferably including polyetheramine, which can further enhance light transmittance, Impact resistance and bonding properties.

Further, the low surface energy fluorine-containing layer is selected from any one or a combination of at least two of fluorine-containing silane, perfluorodecanoic acid, perfluorooctanoic acid and perfluorooctylethyl alcohol, wherein typical but not limited The combination is: a combination of a fluorine-containing silane and a perfluoroantimonic acid, a combination of a fluorine-containing silane and a perfluorooctanoic acid, a combination of a fluorine-containing silane and a perfluorooctylethyl alcohol, a combination of perfluorodecanoic acid and perfluorooctanoic acid, a fluorine-containing silane, A combination of perfluorodecanoic acid and perfluorooctanoic acid; preferably comprising a fluorine-containing silane. The composition of the low surface energy fluorine-containing layer of the present application has strong adhesion to the uneven surface of the epoxy resin layer, avoids problems such as poor compatibility caused by the addition of inorganic ions in the prior art, and forms a firm transparent hydrophobic wear-resistant layer. coating. The low refractive index of fluorosilane allows the coating to have the effect of preventing light reflection and increasing light transmission.

Further, the fluorine-containing silane includes any one or at least two of heptadecylmercaptotriethoxysilane, perfluorodecyltriethoxysilane, and perfluorooctylethyltriethoxysilane. Combination of A but non-limiting combination is: a combination of heptafluorodecyltriethoxysilane and perfluorodecyltriethoxysilane, heptadecafluorodecyltriethoxysilane and perfluorooctylethyl three Combination of ethoxysilanes, combination of perfluorodecyltriethoxysilane and perfluorooctylethyltriethoxysilane, heptadecafluorodecyltriethoxysilane, perfluorodecyltriethoxy A combination of silane and perfluorooctylethyltriethoxysilane; preferably comprising heptadecafluorodecyltriethoxysilane.

In a second aspect, the present application provides a method for preparing a transparent hydrophobic wear-resistant coating according to the first aspect, comprising the steps of:

(1) Preparation of epoxy resin layer:

The epoxy resin and the curing agent are blended in an organic solvent and ultrasonicated to obtain a coating solution. The total content of the epoxy resin and the curing agent in the coating solution is 0.001 to 5 wt%, for example, 0.001 wt%, 0.002 wt%. 0.003 wt%, 0.004 wt%, 0.005 wt%, 0.008 wt%, 0.01 wt%, 0.02 wt%, 0.05 wt%, 0.1 wt%, 0.2 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, 1.5 wt %, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt% or 5wt%, etc., the method of pulling the coating material on the base material to uniformly adhere the coating solution to the surface of the base material, Curing is proposed to obtain an epoxy layer;

(2) Preparation of low surface energy fluorine-containing layer:

The fluorine-containing solution is coated on the epoxy resin layer obtained in the step (1) and dried to obtain a transparent hydrophobic wear-resistant coating.

The method of the present application can prepare the epoxy layer morphology with different surface roughness by changing the concentration of the epoxy resin and the curing agent in the solvent, so that the hydrophobicity of the coating can be controlled. By controlling the coating solution of step (1) to a lower level, and forming an epoxy resin layer of a suitable thickness, and using a pulling method to spontaneously form a microscopic rough surface of the uneven epoxy resin layer during the preparation process, the coating The layer has good interfacial interaction with both the substrate and the fluorine-containing layer, and the bonding property is excellent without affecting the transmittance of the substrate material itself. The epoxy resin and the curing agent are disposed in a solution according to a functional group equivalent.

Further, the organic solvent in the step (1) includes any one or a combination of at least two of a ketone, an ester, an ether alcohol and a chlorinated hydrocarbon, wherein a typical but non-limiting combination is: a ketone Combination with esters, combination of ether alcohols and chlorinated hydrocarbons, combination of ketones and chlorinated hydrocarbons, combination of ketones, esters and chlorinated hydrocarbons, ketones, esters, ether alcohols and A combination of chlorinated hydrocarbons; preferably including ketones, further preferably including acetone and/or methyl ethyl ketone, which have excellent solubility properties for epoxy resins and curing agents.

Further, the pulling speed of the lift coating film in the step (1) is 0.1 to 10 mm/s, for example, 0.1 mm/s, 0.2 mm/s, 0.5 mm/s, 0.8 mm/s, 1 mm/s, 2 mm. /s, 3mm/s, 4mm/s, 5mm/s, 6mm/s, 7mm/s, 8mm/s, 9mm/s or 10mm/s. There is a synergistic effect between the pulling speed and the concentration of the coating solution, and the two factors cooperate to form a suitable microscopic surface of the epoxy layer.

Further, the pulling speed of the lift coating film in the step (1) is 0.1 to 3 mm/s.

Further, the curing in the step (1) is heat curing.

The temperature of the heat curing is 70 to 90 ° C, for example, 70 ° C, 72 ° C, 75 ° C, 78 ° C, 80 ° C, 82 ° C, 85 ° C, 88 ° C or 90 ° C, etc., the first constant temperature is 1 to 3 h, for example 1h, 1.2h, 1.5h, 1.8h, 2h, 2.2h, 2.5h, 2.8h or 3h, etc., then 100 to 120 ° C, such as 100 ° C, 102 ° C, 105 ° C, 108 ° C, 110 ° C, 112 ° C, 115 ° C, 118 ° C or 120 ° C, etc., the second constant temperature of 1 ~ 3h, such as 1h, 1.2h, 1.5h, 1.8h, 2h, 2.2h, 2.5h, 2.8h or 3h.

Optionally, the manner of curing in the step (1) includes any one of a combination of blast drying, natural drying, vacuum drying and freeze drying, or a combination of at least two, preferably blast drying.

Further, the method of drying according to the step (2) comprises any one or a combination of at least two of blast drying, natural drying, vacuum drying and freeze drying; preferably blast drying;

The blast drying temperature is 70-90 ° C, such as 70 ° C, 72 ° C, 75 ° C, 78 ° C, 80 ° C, 82 ° C, 85 ° C, 88 ° C or 90 ° C, etc., the time is 1-3 h, such as 1 h , 1.2h, 1.5h, 1.8h, 2h, 2.2h, 2.5h, 2.8h or 3h.

Further, the base material includes any one of plastic, metal, and glass, or a combination of at least two.

Compared with the prior art, the present application has at least the following beneficial effects:

1. The transparent hydrophobic wear-resistant coating prepared according to the method of the present application has transparency equivalent to glass, and the surface contact angle is above 102°;

2. The method of the present application can prepare the coating morphology with different surface roughness by changing the concentration of the epoxy resin and the curing agent in the solvent, so that the hydrophobicity of the coating is controllable;

3. The transparent hydrophobic wear-resistant coating of the present application does not need to add reinforcing nano-materials, and has excellent mechanical strength itself, can protect plastic, glass and metal surfaces, and avoids supplementation in the prior art. Problems such as difficulty in dispersion and reduction in transparency caused by strong nanoparticles;

4. The transparent hydrophobic wear-resistant coating of the present application has excellent interfacial interaction with the substrate, and has good bonding performance; avoids problems such as adding reinforcing nanoparticles in the prior art and being weak due to poor compatibility;

5. The transparent hydrophobic wear-resistant coating of the present application has excellent scratch resistance, can delay the generation of cracks, and protects the glass;

6. The method of the present application is simple and easy, the raw materials are easy to obtain, the repeatability is good, and the large-scale industrial production is convenient.

DRAWINGS

1 is a water contact angle state diagram of a surface of a transparent hydrophobic wear-resistant coating obtained in Example 1;

2 is a water contact angle state diagram of the surface of the transparent hydrophobic wear-resistant coating obtained in Example 2;

3 is a water contact angle state diagram of the surface of the transparent hydrophobic wear-resistant coating obtained in Example 3;

Figure 4 is a water contact angle state diagram of the surface of the transparent hydrophobic wear-resistant coating obtained in Example 4;

5 is a light transmission performance test of the transparent hydrophobic wear-resistant coating obtained in Example 1;

Figure 6 is an optical micrograph of the epoxy resin coating obtained in Example 1;

Figure 7 is a scratch resistance test of a glass substrate;

Figure 8 is a graph showing the scratch resistance test of the transparent hydrophobic wear-resistant coating obtained in Example 1 on a glass substrate.

Detailed ways

The technical solutions of the present application will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely illustrative of the present invention and are not intended to limit the scope of the claims. The scope of the application is defined by the claims.

Example 1

A transparent hydrophobic wear resistant coating comprising an epoxy layer and a low surface energy fluorine layer arranged in this order from top to bottom.

The preparation steps are as follows:

1) Preparation of epoxy resin coating:

2.63 g of epoxy resin E-44 and 0.697 g of polyetheramine D230 were dissolved in 80 mL of acetone, stirred for 2 h, and sonicated for 30 min to obtain a clear blend solution. Slides (25*25*1mm) were placed in the solution for 5 s, and pulled vertically at a speed of 6 mm/s. The substrate material containing the coating was placed in a forced air oven and cured by heating at 70 ° C. After drying for 2 h, it was dried at 120 ° C for 2 h to obtain an epoxy resin coating having a surface topography.

2) Preparation of low surface energy coating:

To the low surface of the epoxy resin-coated base obtained in step 1), add 2 μL of low surface energy material, evenly wipe the low surface energy, and then put it into a blast oven, dry at 70 ° C for 2 h, and remove it. That is, a transparent hydrophobic wear resistant coating is obtained.

As shown in Figure 1, the coating has a surface contact angle of 113°, as shown in Figure 5, which has similar light transmission properties to the glass surface. As shown in Fig. 6, the epoxy resin forms a rough surface on the surface of the substrate to improve the surface roughness. Comparing Figures 7 and 8, the added transparent hydrophobic wear-resistant coating can effectively improve the scratch resistance of the coating, delay the generation of cracks, and thus function as a protective glass.

Example 2

The preparation steps are as follows:

1) Preparation of epoxy resin coating:

1.16 g of epoxy resin E-44 and 0.307 g of polyetheramine D230 were dissolved in 60 mL of acetone, stirred for 3 h, and sonicated for 15 min to obtain a clear blend solution. Slides (25*25*1mm) were placed in the solution for 10s, and pulled vertically at a speed of 4mm/s. The base material containing the coating was placed in a forced air oven and cured by heating at 70 °C. After drying for 2 h, it was dried at 120 ° C for 2 h to obtain an epoxy resin coating having a surface topography.

2) Preparation of low surface energy coating:

As shown in Figure 2, the coating has a surface contact angle of 111° and the coating has similar light transmission properties to the glass surface.

Example 3

The preparation steps are as follows:

1) Preparation of epoxy resin coating:

0.378 g of epoxy resin E-44 and 0.1 g of polyetheramine D230 were dissolved in 60 mL of acetone, stirred for 1.5 h, and sonicated for 30 min to obtain a clear blend solution. Place the slide (25*25*1mm) The solution was immersed for 12 s, and pulled vertically at a speed of 2 mm/s. The base material containing the coating was placed in a forced air oven to be heated and solidified, dried at 70 ° C for 2 h, and then dried at 120 ° C for 2 h to obtain An epoxy coating with a surface topography.

2) Preparation of low surface energy coating:

As shown in Figure 3, the coating has a surface contact angle of 102° and the coating has similar light transmission properties to the glass surface.

Example 4

The preparation steps are as follows:

1) Preparation of epoxy resin coating:

0.189 g of epoxy resin E-44 and 0.05 g of polyetheramine D230 were dissolved in 60 mL of acetone, stirred for 1 h, and sonicated for 30 min to obtain a clear blend solution. The slide glass (25*25*1mm) was placed in the solution for 15s, and pulled vertically at a speed of 1mm/s. The base material containing the coating was placed in a forced air oven and cured by heating at 70 °C. After drying for 2 h, it was dried at 120 ° C for 2 h to obtain an epoxy resin coating having a surface topography.

2) Preparation of low surface energy coating:

As shown in Figure 4, the coating has a surface contact angle of 98° and the coating has similar light transmission properties to the glass surface.

Example 5

A transparent hydrophobic wear-resistant coating prepared by replacing 80 mL of acetone with 64 mL of methyl ethyl ketone. The other conditions are the same as in Example 1. The surface contact angle of the coating is 113°, which has a similar surface to that of the glass. Light performance.

Example 6

A transparent hydrophobic wear-resistant coating prepared by replacing 60 mL of acetone with 48 mL of methyl ethyl ketone. The other conditions are the same as in Example 2, and the surface contact angle of the coating is 111°, which is similar to the surface of the glass. Light performance.

Example 7

A transparent hydrophobic wear-resistant coating prepared by replacing 60 mL of acetone with 48 mL of methyl ethyl ketone, and other conditions are the same as in Example 3, the surface contact angle of the coating is 102°, and has a similar surface to the glass surface. Light performance.

The Applicant claims that the present application describes the detailed process equipment and process flow of the present application by the above embodiments, but the present application is not limited to the above detailed process equipment and process flow, that is, it does not mean that the application must rely on the above detailed process equipment and The process can only be implemented. It should be apparent to those skilled in the art that any modification of the present application, the equivalent replacement of each raw material of the product of the present application, the addition of an auxiliary component, the selection of a specific manner, and the like, are all within the scope of protection and disclosure of the present application.

Claims

A transparent hydrophobic wear-resistant coating, wherein the transparent hydrophobic wear-resistant coating is composed of an epoxy resin layer and a low surface energy fluorine-containing layer arranged in this order from top to bottom.
The transparent hydrophobic abrasion resistant coating according to claim 1, wherein the epoxy resin layer has a thickness of 5 nm to 5 μm.
The transparent hydrophobic abrasion resistant coating according to claim 2, wherein the epoxy resin layer has a thickness of from 10 nm to 100 nm.
The transparent hydrophobic abrasion resistant coating according to any one of claims 1 to 3, wherein the epoxy resin layer comprises an epoxy resin and a curing agent;

The epoxy resin includes a bisphenol A type epoxy resin and/or a bisphenol F type epoxy resin;

The curing agent includes any one or a combination of at least two of an aromatic amine, a polyether amine, an ethanolamine, an aminopropanol, and an amino alcohol.
The transparent hydrophobic wear-resistant coating according to any one of claims 1 to 4, wherein the low surface energy fluorine-containing layer is selected from the group consisting of fluorine-containing silane, perfluorodecanoic acid, perfluorooctanoic acid, and perfluorooctylethyl Any one or a combination of at least two of the alcohols.
The transparent hydrophobic abrasion resistant coating according to claim 5, wherein said low surface energy fluorine-containing layer is a fluorine-containing silane, and said fluorine-containing silane comprises heptadecafluorodecyltriethoxysilane, perfluoro Any one or a combination of at least two of mercaptotriethoxysilane and perfluorooctylethyltriethoxysilane.
A method of preparing a transparent hydrophobic wear-resistant coating according to any one of claims 1 to 6, comprising the steps of:

(1) Preparation of epoxy resin layer:

The epoxy resin and the curing agent are blended in an organic solvent, and ultrasonically obtained to obtain a coating solution. The total content of the epoxy resin and the curing agent in the coating solution is 0.001 to 5 wt%, and the base material is used as a coating film. The method makes the coating solution uniformly adhere to the surface of the base material, and is cured to obtain an epoxy resin layer; as well as

(2) Preparation of low surface energy fluorine-containing layer:

The fluorine-containing solution is coated on the epoxy resin layer obtained in the step (1) and dried to obtain a transparent hydrophobic wear-resistant coating.
The production method according to claim 7, wherein the organic solvent of the step (1) comprises any one or a combination of at least two of a ketone, an ester, an ether alcohol, and a chlorinated hydrocarbon.
The production method according to claim 8, wherein the ketone is acetone and/or methyl ethyl ketone.
The production method according to any one of claims 7 to 9, wherein the pulling coating film of the step (1) has a pulling speed of 0.1 to 10 mm/s.
The production method according to claim 10, wherein the pulling coating film of the step (1) has a pulling speed of 0.1 to 3 mm/s.
The preparation method according to any one of claims 7 to 11, wherein the curing in the step (1) is heat curing;

Preferably, the temperature of the heat curing is 70-90 ° C, the first constant temperature is 1 to 3 h, then 100 to 120 ° C, and the second constant temperature is 1 to 3 h.
The preparation method according to any one of claims 7 to 11, wherein the method of curing in the step (1) comprises any one or at least two of blast drying, natural drying, vacuum drying, and freeze drying. combination.
The production method according to any one of claims 7 to 13, wherein the method of drying in the step (2) comprises any one or at least two of blast drying, natural drying, vacuum drying, and freeze drying. combination;

Preferably, the blast drying temperature is 70 to 90 ° C for a period of 1 to 3 hours.
The preparation method according to any one of claims 7-14, wherein the substrate material comprises Any one or a combination of at least two of plastic, metal and glass.