CN108517154A - A kind of aqueous, floride-free super hydrophobic coating and preparation method - Google Patents

Abstract

The invention discloses the preparation methods of a kind of water-based system, floride-free super hydrophobic coating.The raw material that the coating is made of following mass fraction is made：Water-based emulsion 2 40%, organic solvent 1 10%, low-surface-energy coupling agent 1 20%, nano-particle 2 30%, water 30 90%, dispersion prepares uniform dispersion.Coating is coated in substrate by the methods of spraying, dip-coating, super-hydrophobic coat is obtained after dry.The coating Static water contact angles are more than 150 degree, and roll angle is at 10 degree or less.Paint preparation technology used in the present invention is simple, environmentally protective, and raw material is simple and easy to get, has wide practical use in automatically cleaning, water-oil separating etc., and is suitble to industrialized large-scale application.

Description

A kind of water-based, fluorine-free superhydrophobic coating and preparation method thereof

technical field

The invention belongs to the field of coating preparation, and in particular relates to a method for preparing a water-based system and a fluorine-free super-hydrophobic coating from an aqueous emulsion.

Background technique

Superhydrophobic coatings, that is, coatings with static water contact angles greater than 150 degrees and rolling angles less than 10 degrees, are receiving more and more attention due to their great application prospects in self-cleaning, oil-water separation, and corrosion protection. focus on. However, the key to preparing superhydrophobic coatings is to construct a rough surface with micro/nano structure, and the surface has low surface free energy. In the methods that have been reported so far, there are more or less problems such as complicated preparation conditions, expensive preparation costs, and difficulty in large-scale production, which makes it difficult to popularize and apply these methods for preparing superhydrophobic coatings. And most of them use a large amount of VOC solvents to disperse low surface energy components (CN101962514A, CN105585928A). In addition, although fluorocarbon materials such as fluorine-containing coupling agents and fluoropropylene polymers have been used to prepare superhydrophobic coatings due to their excellent low surface energy properties, their harm to human health and the environment has gradually been recognized. (Environ. Sci. Technol., 2004, 38, 373-380). Therefore, it is a work of great significance and application value to develop water-based and fluorine-free superhydrophobic coatings with simple preparation methods and low-cost raw materials.

Although a small amount of work on water-based superhydrophobicity has been reported (ACS Appl. Mater. Interfaces 2013, 5, 13419, J. Mater. Chem. A2015, 3, 12880), most of these works use the combination of hydrophilic nanofillers and water-based polymers. The water-based superhydrophobic system is formed by mixing the emulsion of the compound and the weak interfacial interaction of the organic-inorganic components in the coating after film formation, which makes the coating easy to wear and lose the superhydrophobic property. Therefore, the preparation of high-performance water-based, fluorine-free superhydrophobic coatings is still a hot research field.

Contents of the invention

The purpose of the present invention is to solve the above-mentioned problems existing in the prior art, and to provide a water-based, fluorine-free superhydrophobic coating and its preparation method and application. Reduce the impact of VOC solvents on the resource environment, and at the same time, the use of fluorine-free low surface energy coupling agent not only avoids the harm to human body and environment caused by the degradation of fluorine-containing materials, but also reduces the cost. Thus, a superhydrophobic coating with simple preparation method, environmental protection and low cost is obtained, which has broad application prospects in self-cleaning, oil-water separation, anti-corrosion, and the like.

Technical scheme of the present invention

A water-based, fluorine-free super-hydrophobic nano-composite coating, composed of water-based emulsion, inorganic nanoparticles, low surface energy coupling agent, organic solvent and water, the mass percentage of each component is: water-based emulsion 2%-40%, inorganic Nanoparticles 2%-30%, low surface energy coupling agent 1%-20%, organic solvent 1%-10%, water 30%-90%.

Described aqueous emulsion is a kind of in acrylate emulsion, styrene-acrylic emulsion, silicon-acrylic emulsion, polyvinyl acetate emulsion, polyvinyl acetate acrylate emulsion, polyurethane dispersion, ethylene acrylate emulsion or ethylene vinyl acetate emulsion and its For two or more mixed emulsions, the solid content in the emulsion is controlled at 30%-60%.

The inorganic nanoparticles are nano-silica, nano-titanium dioxide, nano-magnesium oxide, nano-zinc oxide, nano-calcium carbonate, nano-alumina or carbon nanotubes or mixed nanoparticles. The diameter of the nanoparticles is 1-500 nanometers.

Described low surface energy coupling agent is octadecyltrimethoxysilane, octadecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, dodecane Trimethoxysilane, dodecyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isopropyltris(dioctylpyrophosphate acyloxy) titanate, mono Alkoxy unsaturated fatty acid titanate, isopropyl dioleic acid acyloxy (dioctyl phosphate acyloxy) titanate or distearoyloxy isopropoxy aluminate and other coupling agents One or more mixed.

The organic solvent is one or more mixtures of ethanol, isopropanol, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether or dipropylene glycol dimethyl ether.

A kind of preparation method of described water-based, fluorine-free superhydrophobic nano-composite coating, the steps are as follows:

1) Add the organic solvent and low surface energy coupling agent into the aqueous emulsion in sequence, and obtain a uniform dispersion after stirring;

2) Uniformly disperse the inorganic nanoparticles in water, add to the above-mentioned dispersion liquid, and stir for 0.5-2 hours to obtain a water-based, fluorine-free super-hydrophobic nano-composite coating.

An application of the water-based, fluorine-free super-hydrophobic nano-composite coating, the coating is sprayed on the surface of the sponge at 60°C, and after drying at 60°C, a sponge with a super-hydrophobic surface can be obtained, which is used for oil-water mixing The system can separate oil phase and water phase.

Or coating the coating on the substrate (such as wood, glass, metal, polymer substrate or paper and other material surfaces), after drying, a super-hydrophobic coating is obtained, and the static water contact angle of the coating surface is greater than 150 degrees, The rolling angle is below 10 degrees; the drying and film forming temperature is controlled at 20-100°C, and it is used in self-cleaning, anti-corrosion and other fields.

Advantages and beneficial effects of the present invention:

1) The present invention uses water as the dispersed phase, avoiding the use of harmful VOC solvents, and the raw materials used are all fluorine-free materials, so that the superhydrophobic coating has the advantages of green and environmental protection;

2) The water-based emulsion, inorganic nanoparticles and low surface energy coupling agent are mixed by a simple method, the steps are simple, and the raw materials are cheap and easy to obtain, which is conducive to industrial application and promotion;

3) The use of the low surface energy coupling agent improves the interfacial compatibility between the inorganic nanoparticles and the polymer phase, and improves the mechanical properties of the coating.

Description of drawings

Fig. 1 is the static water contact angle measurement figure of the superhydrophobic coating that embodiment 2 prepares;

Fig. 2 is the surface SEM figure of the superhydrophobic coating that embodiment 2 prepares;

Fig. 3 is the surface SEM figure of the superhydrophobic coating that embodiment 2 prepares;

Fig. 4 is the surface atomic force microscope figure of the superhydrophobic coating that embodiment 2 prepares;

Fig. 5 is the physical picture of the superhydrophobic coating prepared in embodiment 2 on the glass surface;

Fig. 6 is the physical picture of the superhydrophobic coating prepared in embodiment 4 on the sponge surface.

Detailed ways

The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments, but the technical solution of the present invention is not limited to the following specific embodiments.

Example 1:

Add 3.0 g of ethanol to 15.0 g of aqueous vinegar-acrylic emulsion with a solid content of 40%, stir evenly, add 3.0 g of hexadecylethylmethoxysilane, and continue stirring for 15 minutes.

Add 5.0 g of nano-titanium dioxide particles into 74.0 mL of water, stir to obtain a uniform dispersion, mix the dispersion with the aforementioned dispersion system, and continue stirring for 1 hour to obtain a superhydrophobic nanocomposite coating.

The superhydrophobic nanocomposite coating was prepared, and the obtained superhydrophobic nanocomposite coating was sprayed onto a glass sheet at 60°C by spraying, and then dried at 60°C for 24 hours to obtain a superhydrophobic coating. The water contact angle of the coating is 153 degrees, and the rolling angle is 7.5 degrees.

Example 2:

Add 2.0 g of propylene glycol methyl ether into 5.0 g of aqueous silicon-acrylic emulsion with a solid content of 48%, stir evenly, add 4.0 g of dodecyltriethoxysilane, and continue stirring for 15 minutes.

Add 3.0 g of nano-silica particles into 86.0 mL of water, stir to obtain a uniform dispersion, mix the dispersion with the aforementioned dispersion system, and continue stirring for 30 minutes to obtain a super-hydrophobic coating.

To prepare a superhydrophobic coating, spray the obtained superhydrophobic coating onto a glass sheet at 60°C by spraying, and continue drying at 60°C for 24 hours to obtain a superhydrophobic coating. The water contact angle of the coating is 156 degrees, and the rolling angle is 4.5 degrees. Figures 2, 3 and 4 illustrate that the coating forms a rough micro/nano structure after forming a film on the surface of the substrate. Figure 5 shows that the coating can be applied to the glass surface for self-cleaning applications, and Figure 6 shows that the coating can be applied to sponges, etc. Material surface, thus applied in the field of oil-water separation.

Example 3

Add 6.0g of ethanol to 25.0g of aqueous pure acrylic emulsion with a solid content of 40%, stir evenly, add cetyltrimethoxysilane and cetyltriethoxysilane with a total mass of 7.0g, and continue stirring 15 minutes.

Add 10.0 g of nano-silica particles into 52.0 mL of water, stir to obtain a uniform dispersion, mix the dispersion with the aforementioned dispersion system, and continue stirring for 30 minutes to obtain a super-hydrophobic coating.

To prepare a superhydrophobic coating, spray the obtained superhydrophobic coating onto a glass sheet at 50°C, and continue drying at 60°C for 24 hours to obtain a superhydrophobic coating. The water contact angle of the coating is 157 degrees, and the rolling angle is 5.0 degrees.

Example 4

Add 5.0 g of dipropylene glycol dimethyl ether into 30.0 g of water-based styrene-acrylic emulsion with a solid content of 40%, stir evenly, add 13.0 g of hexadecyltrimethoxysilane, and continue stirring for 15 minutes.

Add 17.0 g of nano-silica particles into 35.0 mL of water, stir to obtain a uniform dispersion, mix the dispersion with the aforementioned dispersion system, and continue stirring for 30 minutes to obtain a super-hydrophobic coating.

To prepare a superhydrophobic coating, spray the obtained superhydrophobic coating onto the surface of the sponge at 60°C, and continue drying at 60°C for 24 hours to obtain a superhydrophobic coating. The water contact angle of the coating is 157 degrees, and the rolling angle is 5.0 degrees.

Example 5

Add 8.0 g of isopropanol to 20.0 g of aqueous silicon acrylic emulsion with a solid content of 48%, stir evenly, add 15.0 g of isopropyl tris(dioctyl pyrophosphate acyloxy) titanate, and continue stirring for 15 minutes.

Add 12.0 g of nano-calcium carbonate particles into 45.0 mL of water, stir to obtain a uniform dispersion, mix the dispersion with the aforementioned dispersion system, and continue stirring for 30 minutes to obtain a super-hydrophobic coating.

To prepare a superhydrophobic coating, spray the obtained superhydrophobic coating onto a glass sheet at 60°C by spraying, and continue drying at 60°C for 24 hours to obtain a superhydrophobic coating. The water contact angle of the coating is 152.5 degrees, and the rolling angle is 8.5 degrees.

Example 6

Add 4.0g of propylene glycol methyl ether into 10.0g of water-based silicone acrylic emulsion with a solid content of 48% and a water-based styrene-acrylic emulsion mixture with a solid content of 40% in a total mass of 10.0g, 6.0g of hexadecyltrimethoxysilane, continue Stir for 15 minutes.

Add 28.0 g of nano-silica particles into 52.0 mL of water, stir to obtain a uniform dispersion, mix the dispersion with the aforementioned dispersion system, and continue stirring for 30 minutes to obtain a super-hydrophobic coating.

To prepare a superhydrophobic coating, spray the obtained superhydrophobic coating onto a glass sheet at 70°C by spraying, and continue drying at 70°C for 24 hours to obtain a superhydrophobic coating. The water contact angle of the coating is 152.5 degrees, and the rolling angle is 8.5 degrees.

Example 7

Add 7.0 g of a mixed solvent of ethanol and propylene glycol methyl ether into 35.0 g of an aqueous styrene-acrylic emulsion with a solid content of 48%, and 11.0 g of hexadecyltrimethoxysilane, and continue stirring for 15 minutes.

Add nano-silica particles and nano-titanium dioxide particles with a total mass of 13.0 g into 34.0 mL of water, and stir to obtain a uniform dispersion. Mix the dispersion with the aforementioned dispersion system, and continue stirring for 30 minutes to obtain a super-hydrophobic coating.

To prepare a superhydrophobic coating, spray the resulting superhydrophobic coating onto a glass sheet at 60°C, and continue drying at 60°C for 24 hours to obtain a superhydrophobic coating. The water contact angle of the coating is 155 degrees, and the rolling angle is 5.5 degrees.

Claims (9)

1. a kind of aqueous, floride-free super-hydrophobic nano composite dope, it is characterised in that the coating is by the component of following mass fraction Mixed preparing forms：

2. aqueous, floride-free super-hydrophobic nano composite dope according to claim 1, which is characterized in that the water-based emulsion For acrylic acid ester emulsion, styrene-acrylic emulsion, silicone acrylic emulsion, polyvinyl acetate emulsion, polyvinyl acetate acrylic acid ester emulsion, poly- ammonia The mixed liquor of ester dispersion liquid, ethylene-acrylate lotion or one kind in ethylene vinyl acetate lotion and its two kinds or more, Solid content in water-based emulsion is controlled in 30%-60%.

3. aqueous, floride-free super-hydrophobic nano composite dope according to claim 1, which is characterized in that the inorganic nano Particle is nano silicon dioxide, nano-titanium dioxide, nano magnesia, nano zine oxide, nano-calcium carbonate, nano aluminium oxide or The mix nanoparticles of one or more of carbon nanotube composition；The nano particle diameter is 1-500 nanometers.

4. aqueous, floride-free super-hydrophobic nano composite dope according to claim 1, which is characterized in that the low-surface-energy Coupling agent is octadecyl trimethoxysilane, octadecyltriethoxy silane, hexadecyl trimethoxy silane, hexadecane Ethyl triethoxy silicane alkane, dodecyltrimethoxysilane, dodecyl triethoxysilane, methyltrimethoxysilane, first Ethyl triethoxy silicane alkane, isopropyl three (dioctylphyrophosphoric acid acyloxy) titanate esters, monoalkoxy unsaturated fatty acid titanate esters, In two oleic acid acyloxy of isopropyl (dioctyl phosphoric acid acyloxy) titanate esters or distearyl acyl-oxygen aluminum isopropoxide acid esters coupling agent One or more mixing.

5. aqueous, floride-free super-hydrophobic nano composite dope according to claim 1, which is characterized in that the organic solvent It is one or more in ethyl alcohol, isopropanol, propylene glycol monomethyl ether, propylene-glycol ethyl ether, propandiol butyl ether or dimethyl ether Mixing.

6. claim 1-5 any one of them is aqueous, the preparation method of floride-free super-hydrophobic nano composite dope, it is characterised in that This approach includes the following steps：

Step 1：Water-based emulsion is mixed and made into dispersion liquid with organic solvent and low-surface-energy coupling agent successively；

Step 2：After inorganic nano-particle is mixed with water, it is added in above-mentioned dispersion liquid and super-hydrophobic is received to get to aqueous, floride-free Rice composite coating.

7. aqueous, floride-free super-hydrophobic nano composite dope the application described in a kind of claim 1-5 any one, feature exist In, the coating is coated on base material, super-hydrophobic coat is made after dry, coating surface Static water contact angles are more than 150 degree, Roll angle is at 10 degree or less；Wherein drying and forming-film temperature control is at 20-100 DEG C.

8. aqueous, floride-free super-hydrophobic nano composite dope application, feature exist according to claim 1-5 any one of them In the coating is used to be coated on timber, glass, metal, polymeric substrates or paper material surface；Can be used in automatically cleaning, Anticorrosion field.

9. aqueous, floride-free super-hydrophobic nano composite dope application, feature exist according to claim 1-5 any one of them In, by affiliated coating be coated on sponge surface, gained sponge be dried after, can be used in water-oil separating.