KR101042001B1 - Conductive and superhydrophobic coatings, and its fabrication method - Google Patents

Abstract

The present invention relates to a conductive super water-repellent coating film and a method for manufacturing the same, wherein a coating solution is formed by adding a silane sol mixture to a carbon nanotube (CNT) dispersion, wherein the silane sol mixture contains a fluorine-based silane and a coating solution is formed. Technical superimposition is a conductive super water-repellent coating film formed by applying a coating solution to a substrate and solidifying the same.

Accordingly, carbon nanotube (CNT) is used as a conductive material, a hydrophobic fluorine silane compound and CNT are mixed to prepare a coating solution, and the coating solution is coated on a substrate to control the surface structure to prevent antistatic and At the same time, there is an advantage that super water repellency is possible.

Conductive Super Water-Repellent Coating Membrane Fluorinated Silane Carbon Nanotube

Description

Conductive superhydrophobic coating film and its manufacturing method {Conductive and superhydrophobic coatings, and its fabrication method}

The present invention relates to a conductive super water-repellent coating film and a method for manufacturing the same, and more specifically, using a carbon nanotube (CNT) as a conductive material, by mixing a hydrophobic fluorine silane compound and CNT to prepare a coating solution, coating The present invention relates to a conductive super water-repellent coating membrane capable of antistatic and at the same time capable of super water repellent by coating a solution on a substrate to control the surface structure.

Generally, when the water contact angle of the surface is 90 degrees or more, it is referred to as a hydrophobic surface. In particular, when the microstructure of the surface is flat, the surface of polytetrafluoroethylene (Teflon ^™ ) is said to be a water repellent surface where water is not adsorbed at a maximum contact angle of 115 degrees. However, on such flat surfaces, the contact angle cannot be increased by more than 120 degrees.

On the other hand, when a micro or nanometer sized structure is formed on the surface, a super water-repellent surface having a water contact angle of 150 degrees or more can be realized.

The super water-repellent coating has a self-cleaning property that is not easily adhered to even if foreign matter such as dust or bacteria is on the surface, because the contact area thereof is very small.

Surface treatment methods for water repellency have been variously introduced as a prior art.

As a water repellent surface treatment method, Korean Patent Application No. 2004-59924 discloses a coating composition comprising a silica solution obtained by partially hydrolyzing and polycondensing one or more organosilane compounds to form a super water-repellent coating layer, a method for preparing the same, and the like The coating method used is described.

In addition, Korean Patent Application No. 2004-74711 discloses a sol-gel coating composition obtained by mixing, hydrolyzing and polycondensing at least one organosilane compound with a solvent in which inorganic particles are dispersed in order to form a transparent non-adhesive coating layer. And coating methods using the same.

In addition, Korean Patent Application No. 2004-83736 discloses an organic material obtained by hydrolyzing and polycondensation of one or more organosilane compounds to form an organic-inorganic hybrid coating layer having a high roughness non-adhesive superhydrophobic surface free of transparency control. A method of preparing a coating composition for mixing a coating solution and an ultrafine nano inorganic particle dispersion and controlling reaction conditions and aging conditions, and a surface treatment process for controlling the texture of a base material using the coating composition thus obtained are described.

As another conventional technology, Korean Patent Application No. 2005-29102 discloses an antimicrobial-water repellent coating composition, a preparation method thereof, and a coating method using the same.

However, the above techniques are excellent in water repellency but do not have functions such as antistatic and electromagnetic shielding.

Therefore, the present invention has been made to solve the above problems of the prior art, to prepare a coating solution by mixing a conductive carbon nanotube (CNT) and a hydrophobic fluorine-based silane compound, coating a coating solution on a substrate It is an object of the present invention to provide a conductive super water-repellent coating film and a method of manufacturing the same, which is capable of antistatic and super water repellent by controlling the surface structure.

The present invention for achieving the above object, to form a coating solution by adding a silane sol mixture to the carbon nanotube (CNT) dispersion, the silane sol mixed solution includes a fluorine-based silane, the coating liquid is formed on the substrate The conductive super water-repellent coating film formed by coating and solidifying, and its manufacturing method are the technical gist.

Here, the carbon nanotube dispersion is an acid treatment step of introducing a hydroxyl group and a carboxyl group to the carbon nanotube (CNT) terminal and the surface using an acid solution, and a solvent for dispersing the acid-treated carbon nanotube (CNT) in a dispersion solvent It is formed through a dispersing step, the silane sol mixture is one or more of tetraalkoxysilanes, trialkoxysilanes, dialkoxysilanes are selected, and fluorine-based silane is mixed with it, it is preferably formed by dissolving it in a solvent. Do.

The substrate is one selected from the group consisting of glass, quartz, glass wafers, silicon wafers, and plastics, and the coating layer is sprayed, dip coated, spin coated, screen coated, ink jet printed, pad printed, knife coated, It is produced by any one of the key coating and gravure coating, and the solidification is solidified using a heat or ultraviolet curing method, the acid solution used in the acid treatment step is in nitric acid, hydrochloric acid, sulfuric acid, hydrogen peroxide and a mixture thereof The carbon nanotube is one selected from the group consisting of single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes, and mixtures thereof.

In addition, the carbon nanotube dispersion solvent used in the solvent dispersion step is acetone, methyl ethyl ketone, methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, ethylene glycol, polyethylene glycol, tetrahydrofuran, dimethylform Amide, dimethylacetamide, N-methyl-2-pyrrolidone, hexane, cyclohexanone, toluene, chloroform, distilled water, dichlorobenzene, dimethylbenzene, trimethylbenzene, pyridine, methylnaphthalene, nitromethane, acrylonitrile, octa At least one selected from the group consisting of decylamine, aniline, and dimethyl sulfoxide, wherein the coating liquid is added with a diluting solvent for controlling the concentration of the coating liquid, and the diluting solvent is acetone, methyl ethyl ketone, methyl alcohol, ethyl alcohol, Isopropyl alcohol, butyl alcohol, ethylene glycol, polyethylene glycol, tetrahydrofuran, dimethylformamide, dimethyl acet Amide, N-methyl-2-pyrrolidone, hexane, cyclohexanone, toluene, chloroform, distilled water, dichlorobenzene, dimethylbenzene, trimethylbenzene, pyridine, methylnaphthalene, nitromethane, acrylonitrile, octadecylamine, aniline , Dimethyl sulfoxide, methylene chloride, and mixtures thereof. The dispersion solvent and dilution solvent are preferably used as a dissolving solvent.

Meanwhile, the coating solution contains one or more nanoparticles of SiO ₂ , ZrO ₂ , Al ₂ O ₃ , TiO ₂ , SiO ₂ , gold, and silver, and the carbon nanotubes have an outer diameter of 30 nm or less, and the silane sol mixed solution The silane contained in is added in an amount of 30 to 99 parts by weight based on 100 parts by weight of the carbon nanotubes and the silane mixture, and the coating film has a contact angle of water of 150 degrees or more, a sheet resistance of 10 ⁶ Ω / sq or less, and the fluorine-based The silane is tridecafluorooctyltriethoxysilane, trifluoropropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, and heptadecafluorodecyltrimethoxysilane. It is preferably selected from the group consisting of silane (heptadecafluorodecyltriisopropoxysilane).

The present invention as described above has the effect of forming a super water-repellent coating film having a self-cleaning function to reject dust, water and the like.

In addition, there is an effect that a coating film having a combination of various functions such as antistatic and electromagnetic shielding is formed by having conductivity.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

In the method for producing an antistatic coating film using carbon nanotubes according to the present invention, an acid treatment step of acid treatment of carbon nanotubes and a solvent dispersion step of dispersing the acid-treated carbon nanotubes in a dispersion solvent are performed. A dispersion is formed, and the formed dispersion is mixed with a silane sol mixture containing fluorine-based solazole to form a coating solution, and then the formed coating solution is applied to a substrate and solidified.

The acid treatment step is to introduce a hydroxyl group and a carboxyl group on the carbon nanotube (CNT) terminal and the surface using an acid solution, the acid solution used in the acid treatment step is nitric acid, hydrochloric acid, sulfuric acid, hydrogen peroxide and a mixture thereof Select one to use and disperse the carbon nanotubes in an acid solution, and then proceed to the method of filtration and drying. After the acid treatment step, a carbon nanotube having a hydroxyl group and a carboxyl group introduced into the terminal and surface is obtained.

Here, the carbon nanotubes are selected from single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes, and mixtures thereof, and those having an average outer diameter of 30 nm are used.

Next, a solvent dispersion step of carbon nanotubes is performed, and the acid-treated carbon nanotubes are mixed and dispersed in a dispersion solvent. The dispersion solvents are acetone, methyl ethyl ketone, methyl alcohol, ethyl alcohol, and isopropyl. Alcohol, butyl alcohol, ethylene glycol, polyethylene glycol, tetrahydrofuran, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, hexane, cyclohexanone, toluene, chloroform, distilled water, dichloro One or more of benzene, dimethylbenzene, trimethylbenzene, pyridine, methylnaphthalene, nitromethane, acrylonitrile, octadecylamine, aniline, and dimethyl sulfoxide are used to complete the carbon nanotube dispersion.

Next, in the process of forming a silane sol mixture, one or more of tetraalkoxysilanes, trialkoxysilanes, and dialkoxysilanes are selected, fluorine-based silanes are mixed therein, and then dissolved in a solvent to form.

The fluorine silane is a fluorine silane, tridecafluorooctyltriethoxysilane, trifluoropropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane and heptadecafluoro One of the decadetrifluoropropylsilanes is used.

Then, the carbon nanotube dispersion and the silane sol mixed solution are mixed to form a coating solution. And dilute solvent may be added to adjust the concentration of the coating solution.

Here, the diluent solvent is acetone, methyl ethyl ketone, methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, ethylene glycol, polyethylene glycol, tetrahydrofuran, dimethylformamide, dimethylacetamide, N- Methyl-2-pyrrolidone, hexane, cyclohexanone, toluene, chloroform, distilled water, dichlorobenzene, dimethylbenzene, trimethylbenzene, pyridine, methylnaphthalene, nitromethane, acrylonitrile, octadecylamine, aniline, dimethyl sulfoxide One selected from methylene chloride and mixtures thereof is used.

The dissolving solvent may be a dispersion solvent or a dilution solvent depending on the type of the silane sol.

The coating liquid formed above is coated on a substrate for use as a conductive super water-repellent coating film, and since the concentration should be adjusted according to the coating method, the diluent solvent may be further added to the coating liquid as described above. same.

The coating liquid diluted to an appropriate concentration is coated on the substrate by any one of spraying, dip coating, spin coating, screen coating, inkjet printing, pad printing, knife coating, key coating and gravure coating. Herein, the substrate may use a variety of conductive or non-conductive substrates due to the excellent reactivity and electrical conductivity of carbon nanotubes, and preferably one selected from the group consisting of glass, quartz, glass wafers, silicon wafers, and plastics. Can be used.

By the above coating method, a transparent conductive super water-repellent coating film on the upper surface of the substrate is coated with a thickness of several tens of nanometers to several tens of micrometers depending on the use, and the conductive super water-repellent by drying and solidifying process using a heat or ultraviolet curing method The coating film is to be completed.

Here, if necessary, the coating solution may contain one or more nanoparticles of SiO ₂ , ZrO ₂ , Al ₂ O ₃ , TiO ₂ , SiO ₂ , gold, and silver.

Hereinafter, embodiments of the present invention will be described in detail.

 ≪ Example 1 >

As Example 1 of the present invention, the present invention relates to a technique of forming a conductive super water-repellent coating film by coating a coating liquid mixed with carbon nanotubes / silazole to a substrate.

10 mg of acid-treated carbon nanotubes and 100 ml of ethanol (Ethanol) solvent were mixed in an Erlenmeyer flask and dispersed for 6 hours by an ultrasonic wave to prepare a carbon nanotube solution.

The solution is mixed with a silane sol solution as a binder, wherein the silane sol is 8 mg of tetraethyl orthosilicate (TEOS), 2 mg of heptadecafluorodecyltrimethoxysilane, 3 g of water, 0.1 g of hydrochloric acid, And 80g of ethanol was mixed to prepare for 24 hours at room temperature.

The silane sol solution prepared above was added to the carbon nanotube dispersion, additionally silica nanoparticles were added, and then dispersed for 2 hours by an ultrasonic wave to prepare a carbon nanotube silane binder mixed coating solution.

The carbon nanotube / silane sol mixed coating solution was applied to a glass or polymer substrate using a spray coater. At this time, the temperature of the substrate was performed at a temperature higher than the boiling point of the dispersion solvent.

1 is a conceptual view showing a photo measuring the surface resistance of the coating film according to the present invention, Figure 2 is a view showing a picture showing the shape of the water repellent on the coating film according to the present invention, Figure 3 is a water repellent coating film It is a figure which shows the enlarged cross-sectional photograph which shows the shape to become. As shown, in the embodiment of the present invention the water was water repellent, the sheet resistance was 10 ⁶ Ω / sq or less.

The sheet resistance, transmittance, and contact angle of water of each conductive film prepared below were measured, and the surface morphology of the thin film was observed using an electron scanning microscope, and the results are shown in the table below.

≪ Example 2 >

As Example 2 of the present invention, a conductive super water-repellent coating film using carbon nanotubes was prepared in the same manner as in Example 1, and was performed by increasing the amount of heptadecafluorodecyltrimethoxysilane to 8 mg.

<Example 3>

As Example 3 of the present invention, it was prepared in the same manner as in Example 1 of the conductive super water-repellent coating technology using carbon nanotubes, heptadecafluorodecyltrimethoxysilane to heptadecafluorodecyltriisopropoxysilane Replacement was performed.

<Example 4>

As Example 4 of the present invention, it was prepared in the same manner as in Example 1 of the conductive super water-repellent coating technology using carbon nanotubes, and was carried out without adding silica nanoparticles when mixing the silane sol and carbon nanotube dispersion. In this case, the water contact angle is 150 degrees or more, but the hysteresis of the water contact angle is larger than that of the first embodiment.

<Comparative Example 1>

In Comparative Example 1 of the present invention, carbon nanotubes were prepared in the same manner as in Example 1 of the conductive super water-repellent coating technique, and only 10 mg of tetraethyl orthosilicate (TEOS) and 2.5 in water were used in the preparation of the silane sol. g, hydrochloric acid 0.09g, and ethanol 50g were mixed and prepared at room temperature for 24 hours.

 <Comparative Example 2>

As Comparative Example 2 of the present invention, it was prepared in the same manner as in Example 1 of the conductive super water-repellent coating technique using carbon nanotubes, it was carried out by replacing the heptadecafluorodecyltrimethoxysilane with trimethoxy silane.

That is, in Comparative Examples 1 and 2, no fluorine silane was used.

Next, sheet resistance, transmittance, and contact angle of water of the conductive films according to the examples and the comparative examples were measured, and the surface morphology of the thin film was observed using an electron scanning microscope. will be.

As described above, in the case of the coating film according to the embodiment of the present invention, the water contact angle was found to be super water-repellent of 150 degrees or more, and the sheet resistance was also 10 ⁶ Ω / sq or less, and the transmittance was also excellent in 80 or more. .

On the other hand, in the case of the comparative example without the use of fluorine-based silane, the sheet resistance and permeability were similar to the examples, but the water contact angle was less than 5 degrees or 120 degrees, it was found that the super water repellent was not.

1-a conceptual diagram showing a photo measuring the surface resistance of the coating film according to the present invention.

Figure 2-Figure showing a photograph showing the shape of the water repellent on the coating film according to the invention.

Figure 3-an enlarged cross-sectional view showing the shape of the water repellent on the coating film.

Claims (19)

A coating solution is formed by adding a silane sol mixture to a carbon nanotube (CNT) dispersion formed through an acid treatment step of introducing a hydroxyl group and a carboxyl group to the carbon nanotube (CNT) terminal and surface, wherein the silane sol mixture contains a fluorine-based silane. And a coating solution is formed, and the coating solution is formed on the substrate to solidify the coating solution. The method of claim 1, wherein the carbon nanotube dispersion is formed through a solvent dispersion step of dispersing the acid-treated carbon nanotubes (CNT) in a dispersion solvent. The method of claim 2, wherein the silane sol mixture is selected from one or more of tetraalkoxysilanes, trialkoxysilanes, dialkoxysilanes, fluorine-based silane is mixed, and then dissolved in a solvent to form Method for producing a conductive super water-repellent coating film. The method of claim 3, wherein the substrate is one selected from the group consisting of glass, quartz, glass wafers, silicon wafers, and plastics. The conductive super water-repellent coating film of claim 3, wherein the coating film is formed by any one of spraying, dip coating, spin coating, screen coating, inkjet printing, pad printing, knife coating, key coating and gravure coating. Manufacturing method. The method of claim 3, wherein the solidification is performed by using a heat or ultraviolet curing method. The method of claim 3, wherein the acid solution used in the acid treatment step is one selected from nitric acid, hydrochloric acid, sulfuric acid, hydrogen peroxide, and a mixture thereof. The method of claim 3, wherein the carbon nanotubes are made of one selected from single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes, and mixtures thereof. According to claim 3, wherein the carbon nanotube dispersion solvent used in the solvent dispersion step is acetone, methyl ethyl ketone, methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, ethylene glycol, polyethylene glycol, tetrahydro Furan, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, hexane, cyclohexanone, toluene, chloroform, distilled water, dichlorobenzene, dimethylbenzene, trimethylbenzene, pyridine, methylnaphthalene, nitromethane, A method for producing a conductive super water-repellent coating film, characterized in that at least one member selected from the group consisting of acrylonitrile, octadecylamine, aniline, dimethyl sulfoxide. 10. The method of claim 9, wherein the coating solution is a method for producing a conductive super water-repellent coating film, characterized in that a diluent solvent is added to control the concentration of the coating solution. The method of claim 10, wherein the dilution solvent is acetone, methyl ethyl ketone, methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, ethylene glycol, polyethylene glycol, tetrahydrofuran, dimethylformamide, dimethylacetamide , N-methyl-2-pyrrolidone, hexane, cyclohexanone, toluene, chloroform, distilled water, dichlorobenzene, dimethylbenzene, trimethylbenzene, pyridine, methylnaphthalene, nitromethane, acrylonitrile, octadecylamine, aniline, Method for producing a conductive super water-repellent coating film, characterized in that one selected from dimethyl sulfoxide, methylene chloride and mixtures thereof. The method of claim 11, wherein the dispersion solvent and the dilution solvent are used as a dissolving solvent. The method of claim 3, wherein the coating solution contains one or more nanoparticles of SiO ₂ , ZrO ₂ , Al ₂ O ₃ , TiO ₂ , SiO ₂ , gold, and silver. The method of claim 3, wherein the carbon nanotubes have an outer diameter of 30 nm or less. According to claim 3, The silane contained in the silane sol mixture, Method for producing a conductive super water-repellent coating film, characterized in that added to 30 to 99 parts by weight based on 100 parts by weight of carbon nanotubes and silane mixture. The method of claim 3, wherein the coating film has a contact angle with respect to water of 150 degrees or more. The method of claim 16, wherein the coating film has a sheet resistance of 10 ⁶ Ω / sq or less. According to claim 3, The fluorine-based silane, tridecafluorooctyltriethoxysilane (tridecafluorooctyltriethoxysilane), trifluoropropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane (heptadecafluorodecyltrimethoxysilane) Heptadecafluorodecyl triisopropoxysilane (heptadecafluorodecyltriisopropoxysilane) A method for producing a conductive super water-repellent coating film, characterized in that selected from the group consisting of. A conductive super water-repellent coating film formed by the method according to any one of claims 1 to 18.

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