KR102210567B1 - Surface treatment method and apparatus for making superhydrophobic and high temperature resistant surface - Google Patents

Abstract

The present invention relates to a method and apparatus for treating a surface of a highly heat-resistant super water-repellent, in an embodiment, comprising: performing a blasting treatment on a surface of a substrate to form irregularities so that the surface of the substrate has a predetermined range of roughness; And forming a super-water-repellent coating film by spraying a coating solution onto the surface of the substrate by means of suspension plasma spray coating, wherein the coating solution includes (i) fluorine (F), nitrogen (N), and carbon (C). , Or a slurry solution in which fine particles of metal oxide doped with one of silicon (Si) are dispersed in a solvent; Or (ii) a slurry solution in which metal oxide microparticles are dispersed in a solvent and metal oxide microparticles doped with one of fluorine (F), nitrogen (N), carbon (C), or silicon (Si) are dispersed in a solvent. A slurry solution; Disclosed is a high heat-resistant super water-repellent surface treatment method, characterized in that.

Description

Surface treatment method and apparatus for making superhydrophobic and high temperature resistant surface}

The present invention relates to a highly heat-resistant super-water-repellent surface treatment method, and more particularly, to a surface treatment method to have a highly heat-resistant and super-water-repellent coating surface by a novel surface coating method based on a metal oxide.

The super water-repellent property that reduces the contact with water on the surface is due to the chemical property of low surface energy and the surface structure with a small contact area.Home/life products (non-stick surfaces of kitchen containers such as frying pans and rice cookers, electronic products) A lot of research is being conducted as a technology that is applied to a variety of applications, from exterior materials of exterior materials, self-cleaning of windows and doors) to transport aircraft/plants in industrial sites (reinforcement of visibility of automobiles, ships, and aircraft, antifouling, icing prevention, etc.).

However, most of the existing technologies use a method of coating a fluorine organic compound or silicon organic compound-based material alone or in combination, so durability and stability are difficult to apply to a long time use and various environments (including high temperature and high pressure). have. Therefore, there is a need for improvement in durability and stability of high temperature and high pressure, which are obstacles to practical application at present.

Patent Document 1: Korean Patent Application Publication No. 2017-0026985 (published on March 9, 2017) Patent Document 2: Korean Patent Registration No. 10-0871877 (announced on December 3, 2008)

According to an embodiment of the present invention, inorganic materials having low surface energy are coated in a single process on various surfaces exposed to various environments (room temperature, real pressure, as well as high temperature, high pressure, etc.), thereby economically performing surface roughness and chemical surface modification at the same time. It aims to form a super water-repellent surface having durability and stability even when exposed to various environments.

According to an embodiment of the present invention, an inorganic metal oxide is used to form a highly heat-resistant super water-repellent surface, and a single process of coating and heat treatment is performed at once by coating the surface by a plasma spray coating method. Metal oxides can be used in a state doped with fluorine (F), nitrogen (N), carbon (C), and silicon (Si) in order to have a composition with low surface energy, and nanoparticles can be coated on the surface at low temperatures. It can take the form of particles.

Plasma thermal spray coating is a method of coating the substrate by melting the surface of the nanoparticles while spraying the nanoparticle coating solution onto the substrate surface. Unlike conventional thermal spray coating, which uses a solution-based coating solution, the process is possible at a low temperature. , Very ?湛? By forming a coating film with a film thickness, it is possible to achieve a super water-repellent surface by increasing the adhesive force and having the roughness of the surface.

According to an embodiment of the present invention, it is possible to form a super-water-repellent surface having stability even at 500 degrees Celsius or higher. In the case of a conventional super water-repellent coating using a fluorine-based polymer organic material or a carbon composite, a high contact angle of 100° or more can be formed, but at a temperature of 200° C. or more, it is decomposed/denatured, making it difficult to maintain performance. However, according to the present invention, there is an advantage in that a high heat-resistant super water-repellent coating can be applied that maintains super water-repellent properties even at a temperature of 500 degrees Celsius or higher based on the high temperature stability of the metal oxide.

According to an embodiment of the present invention, a super water-repellent surface having a contact angle of 150° or more may be formed. Conventionally, as a chemical property of a water-repellent material, it was common to have a contact angle of 90 to 110°, but according to the present invention, the surface may be roughened by coating a slurry using fine particles, and the contact angle may have a super water-repellent property of 150° or more.

According to an embodiment of the present invention, the super water-repellent coating surface may have a wear resistance of 8H or more. In the existing technology, the outermost coating surface, which determines the super-water repellent property, is easily peeled off even with small scratches and ridge phenomenon occurs, but in the present invention, since the super-water-repellent coating surface is formed with an inorganic material-based coating material, it can withstand scratches and impacts. Has high wear resistance.

In addition, according to an embodiment of the present invention, since it has excellent thermal stability and does not easily decompose, it provides a super water-repellent surface without emission of harmful substances. Conventionally, fluorine compounds based on organic substances or silicon organic compounds were eluted at high temperatures, causing harmful factors to the human body and the environment, but according to the present invention, the elution of harmful substances is fundamentally blocked by the chemical combination of metal oxides and doping elements.

1 is a flow chart for explaining a surface coating method according to an embodiment of the present invention,
2 is a schematic diagram of a suspension plasma coating apparatus used for surface coating according to an embodiment;
3 to 5 are views for explaining a nozzle part of a suspension plasma coating apparatus according to an alternative embodiment;
6 is a view showing an exemplary configuration of a super water-repellent coating layer coated on a substrate according to an embodiment;
7 is a view for explaining the effect of the surface coating according to an embodiment of the present invention.

The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments related to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In the present specification, when a component is referred to as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them.

In the present specification, when terms such as first and second are used to describe components, these components should not be limited by these terms. These terms are only used to distinguish one component from another component. The embodiments described and illustrated herein also include complementary embodiments thereof.

In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification, "comprise" and/or "comprising" does not exclude the presence or addition of one or more other components.

Hereinafter, the present invention will be described in detail with reference to the drawings. In describing the specific embodiments below, a number of specific contents have been prepared to explain the invention in more detail and to aid understanding. However, readers who have knowledge in this field to the extent that they can understand the present invention can recognize that it can be used without these various specific contents. In some cases, it should be mentioned in advance that parts that are commonly known in describing the invention and are not significantly related to the invention are not described in order to avoid confusion in describing the invention.

1 is a flow chart for explaining a surface coating method according to an embodiment of the present invention.

The surface coating method according to an embodiment may include a substrate pretreatment step (S10), a blasting treatment step (S20), a super water-repellent coating film formation step (S30), and a substrate post-treatment step (S40). In one embodiment, at least one of the substrate pre-treatment step S10, the blasting treatment step S20, and the post-treatment step S40 may be omitted.

In one embodiment, the pre-treatment step (S10) is a step of pre-treating the surface of the substrate to be super-water-repellent coating. Here,'substrate' is an object that forms a super-water-repellent coating, for example, various cooking products such as frying pans and pots, household products such as heaters, fans, refrigerators, irons, etc., or various construction materials, parts for private use, and parts of the plant site. It can be any product such as an industrial product. In addition, in the present invention, the substrate may be made of metal, ceramic, or plastic, and is not particularly limited.

In one embodiment, various contaminants adhering to the surface of the substrate may be removed and cleaned by the pretreatment step (S10). For example, in this step (S10), contaminants on the surface of the substrate may be removed and washed using an organic solvent or various additives.

A blasting treatment may be performed on the surface of the substrate in step S20 after the pretreatment step S10. The blasting step (S20) is to make the surface of the substrate have a roughness (roughness) of a predetermined size, and if the surface of the substrate has a predetermined roughness, the coating film on the surface of the substrate is much easier in the coating film forming step (S30) to be described later. It can be coated and can increase the adhesion with the coating film.

The blasting treatment may be performed by sand blasting, for example. In one embodiment, the blast-treated substrate surface may have a surface roughness value of RMS of several micrometers (um) or less, and preferably, it is appropriate to have a surface roughness of 1 μm or less.

Next, in step S30, a super-water-repellent coating film is formed on the surface of the blasted substrate. In one embodiment, a super water-repellent coating film may be formed by spraying a suspension solution for coating onto the surface of the substrate by means of suspension plasma spray coating.

Suspension Plasma Spray is a method of forming a thermal spray film on the surface of the substrate by injecting a suspension obtained by dispersing fine raw material particles in a solvent such as water or ethanol into a plasma jet and spraying it toward the substrate surface. That's the way. In an embodiment of the present invention, a coating solution in the form of a slurry is prepared, and the slurry solution is sprayed on the surface of a substrate by plasma spraying to form a coating film. In this specification, a suspension, a slurry, and a sol will be used without distinction unless there is a benefit of special distinction.

In the first embodiment, the coating solution may be a solution in the form of a slurry in which fine particles of fluorine-containing metal oxide are dispersed in a solvent. Here, the'fluorine-containing metal oxide microparticles' are nanoparticles of a metal oxide in which fluorine (F) is added (doped) to the metal oxide.

In this case,'metal oxide'

(i) an oxide of one of the elements capable of forming oxides from Group 1 to Group 16 elements;

(ii) an oxide of one of lanthanum and rare earth metals including scandium (Sc) and yttrium (Y);

(iii) sodium (Na), potassium (K), rubidium (Rb), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), scandium (Sc), yttrium (Y), Titanium (Ti), zirconium (Zr), vanadium (V), neovitium (Nb), chromium (Cr), molybdenum (Mo), manganese (Mn), technetium (Tc), iron (Fe), ruthenium (Re), cobalt (Co), rhodium (Rh), nickel (Ni), copper (Cu), zinc (Zn), aluminum (AI), gallium (Ga), indium (In), thallium (Tl) , An oxide of one of silicon (Si), tin (Sn), antimony (Sb), bismuth (Bi), and tellurium (Te); And

(iv) an oxide of a composition consisting of two or more elements selected from among the alkali metal, alkaline earth metal, lanthanum group, artinium group, transition metal, post-transition metal, and metalloid;

It may contain one of. Strictly speaking, silicon (Si), antimony (Sb), tellurium (Te), and the like are metalloids, but in this specification, they are collectively referred to as'metal oxides' together with oxides such as other metals.

For example, when a silicon oxide (eg, SiO ₂ ) is used as the metal oxide, the'fluorine-containing metal oxide microparticles' may be F-SiO ₂ (silicon oxyfluoride) nanoparticles containing fluorine in the silicon oxide. In the present invention, the fluorine-containing metal oxide contains fluorine instead of oxygen, which can be prepared by using a compound that provides fluorine when synthesizing the metal oxide. It is preferable that the size of the fluorine-containing metal oxide microparticles is 10 nm to 500 nm.

In this way, fluorine is added (doped) to the metal oxide to lower the surface energy. Accordingly, in an alternative embodiment, other materials for lowering surface energy, such as nitrogen (N), carbon (C), or silicon (Si), may be added (doped) to the metal oxide instead of fluorine.

The solvent used in the slurry solution for coating in the present invention may include, for example, at least one of water, ethanol, methanol, isopropanol, benzene, toluene, and a mixed solvent thereof. In addition, other solutions or additives may be further added to the coating slurry solution according to a specific embodiment. For example, in one embodiment, the coating slurry solution may further include a binder, a dispersant, and/or a functional filler.

As described above, conventionally, when fluorine (F) is used for super water-repellent coating, a fluorine-based polymer compound is mainly used, but in the embodiment of the present invention, a slurry form in which fluorine-containing metal oxide nanoparticles are dispersed in a solvent without using a polymer compound. A solution of is used, and this slurry-type solution is coated on the surface of the substrate by plasma spray coating.

In the second embodiment, the coating solution of the present invention is a slurry solution of metal oxide fine particles (hereinafter also referred to as "first slurry solution") and a slurry solution of fluorine-containing metal oxide fine particles (hereinafter also referred to as "second slurry solution"). It may include).

Here, the'metal oxide fine particle' is a nanometer-sized particle of the metal oxide described above, and may mean, for example, a metal oxide fine particle having a size between 10 nm and 500 nm. In general, silicon oxide (SiO ₂ ) is often used as a metal oxide fine particle. However, alternatively, other metal oxides (eg, MgO or TiO _x ) may be used to increase the adhesion between the substrate and the super water-repellent coating layer.

The'fluorine-containing metal oxide microparticles' is the'fluorine-containing metal oxide microparticles', and the size of the fluorine-containing metal oxide microparticles is preferably 10 nm to 500 nm.

In addition, the solvent used in the coating solution of the second embodiment may include, for example, at least one of water, ethanol, methanol, isopropanol, benzene, toluene, and a mixed solvent thereof, depending on the specific embodiment. Additional solutions or additives may be added.

A slurry solution of metal oxide microparticles (first slurry solution) and a slurry solution of fluorine-containing metal oxide microparticles (second slurry solution) may be prepared in separate storage containers and sequentially coated on the substrate during the plasma coating process. , A mixed slurry solution obtained by mixing the first slurry solution and the second slurry solution may be prepared in one storage container and coated on the substrate by plasma coating.

In this regard, FIG. 2 schematically illustrates a suspension plasma coating apparatus used for surface coating according to an embodiment. Referring to the drawings, the suspension plasma coating apparatus according to an embodiment includes a plasma generating unit 10 generating plasma, one or more suspension storage units 30 and 50 accommodating the suspension, and a cleaning solution for cleaning the nozzle and the supply pipe. It may include a washing liquid storage unit 40 to accommodate, a suspension controller 60 having a function of sequentially supplying or mixing suspensions, and a suspension supply nozzle 15 for supplying the suspension to the plasma generating unit 10.

The plasma generating unit 10 may be composed of an anode 11, a cathode 12, a gas injection port 13, and an outlet 14. The gas inlet 13 is formed between the anode 11 and the cathode 12, and, for example, a heat source gas including at least one of argon, helium, hydrogen, nitrogen gas, and air is injected through the gas inlet 13. The heat source gas injected into the gas injection port 13 is converted into a plasma flame by the high voltage and high power applied between the anode 11 and the cathode 12 and is injected through the outlet 14.

In the illustrated embodiment, the first suspension storage unit 30 stores a first slurry solution, that is, a slurry solution of metal oxide fine particles, and the second suspension storage unit 50 is a second slurry solution, that is, a fluorine-containing metal oxide. A slurry solution of fine particles can be stored.

The first suspension storage unit 30 may include a stirrer 31 for stirring so that the metal oxide fine particles are uniformly dispersed in the solvent while the coating solution of the metal oxide fine particles is stored, Similarly, the second suspension storage unit 50 may also include a stirrer 51. In an alternative embodiment, instead of a stirrer, a device capable of maintaining a uniform dispersion degree of the stored solution through a method such as ultrasound or vibration may be provided.

The coating solution of the first and second suspension storage units 30 and 50 is supplied to the suspension controller 60 through the first supply pipe P11 and the third supply pipe P13, respectively, and the suspension controller 60 is one Only the coating solution of is selected or two or more coating solutions are mixed and supplied to the nozzle 15 through the nozzle supply pipe P2. The coating solution sprayed from the nozzle 15 is sprayed onto the surface of the substrate 20 by a plasma jet, and a coating layer may be formed on the surface of the substrate 20.

In one embodiment, the nozzle 15 is disposed adjacent to the upper portion of the outlet 14 of the plasma generating unit 10 to spray the coating solution through the nozzle 15. However, in an alternative embodiment, the position or number of the nozzles 15 may be different. In this regard, FIGS. 3 to 5 exemplarily show the nozzle shape or position in an alternative embodiment.

In the alternative embodiment of FIG. 3, a plurality of nozzles 15 may be disposed radially spaced apart from the outlet 14 of the plasma generating unit 10 at regular intervals, and the coating solution in each nozzle 15 It can be sprayed towards the outlet 14. In the illustrated embodiment, four nozzles 15 are illustrated, but the number or spacing of the nozzles 15 may vary according to specific embodiments.

In the embodiment of Fig. 4, the nozzle 16 is disposed inside the cathode 12. That is, the nozzle 16 is disposed in a coaxial structure with the cathode 12 and is configured to spray the coating solution toward the outlet 14. Accordingly, when the heat source gas is converted into a plasma flame by the high voltage between the anode 11 and the cathode 12 and is sprayed to the outlet 14, the coating solution sprayed from the nozzle 16 may be mixed and sprayed. .

5 shows an embodiment in which a disk-shaped nozzle cap 70 is coupled to the outlet 14 of the plasma generating unit 10, and Fig. 5(a) shows the plasma generating unit 10 and the nozzle cap. It is a schematic cross-sectional view of 70 and FIG. 5(b) schematically shows a perspective view of the nozzle cap 70 taken along line AA′ of FIG. 5(a).

As can be seen from the drawing, the nozzle cap 70 has a disk shape having a predetermined thickness in the injection direction of the plasma jet, and a through hole 74 through which the plasma jet passes is formed in the center and has an empty space therein. That is, the outer circumferential surface 71 and the inner circumferential surface 72 of the nozzle cap 70 surround the empty space inside, and one side 73 is coupled to the outlet 14 of the plasma generating unit 10. The coating solution supplied from the suspension controller 60 flows into the inner space of the nozzle cap 70 through the supply pipe P2 to fill the inner space, and through one or more spray holes 75 formed on the inner circumferential surface 72 The coating solution is sprayed toward the through hole 74. When the nozzle cap 70 is used as described above, the coating solution may be uniformly sprayed in the radial direction toward the plasma jet.

In the illustrated embodiment, the inner diameter of the inner circumferential surface 72 of the nozzle cap 70 is shown to be the same as the diameter of the outlet 14 of the plasma generating unit 10, and an empty space is formed throughout the nozzle cap 70. However, in an alternative embodiment, for example, the diameter of the inner circumferential surface 72 may be larger than the diameter of the outlet 14, and the empty space may be formed only in a partial area inside the nozzle cap 70.

The super water-repellent surface coating may be applied to the substrate 20 in various ways as shown in FIG. 6 by using the above-described suspension plasma coating apparatus.

For example, a fine particle slurry solution ("first slurry solution") of a metal oxide (for example, SiO ₂ ) is stored in the first suspension storage unit 30, and a fluorine-containing metal oxide (for example, in the second suspension storage unit 50) Assuming that the F-SiO ₂ ) fine particle slurry solution ("second slurry solution") is stored, as shown in Fig. 6(a), only the fluorine-containing metal oxide layer 100 is coated on the substrate 20 A water-repellent coating surface can be formed. In this case, the first slurry solution of the first suspension storage unit 30 was not used, and only the second slurry solution of the second suspension storage unit 50 was used to coat the coating.

As another embodiment, a mixed layer 200 of metal oxide microparticles and fluorine-containing metal oxide microparticles may be formed on the substrate 20 as shown in FIG. 6B. In this case, both the supply pipe P11 of the first suspension storage unit 30 and the supply pipe P13 of the second suspension storage unit 50 are opened, and the first and second slurry solutions are appropriately supplied from the suspension controller 60. Such a mixed layer may be formed by mixing and supplying the mixed slurry to the nozzle 15 through the supply pipe P2. Alternatively, plasma coating is performed by storing a mixed slurry solution obtained by premixing the first slurry solution and the second slurry solution in one storage unit (eg, the first storage unit 30 or the second storage unit 50). You can also do it.

6(c) shows an embodiment in which a metal oxide layer 300 and a fluorine-containing metal oxide layer 400 are sequentially coated on the substrate 20. Since the fluorine-containing metal oxide has low surface energy and may have poor adhesion to the substrate, firstly, plasma coating the first slurry solution of the metal oxide on the substrate 20 as shown in Fig. 6(c), and then storing the second suspension. When the second slurry solution of the part 50 is coated on the substrate 20, the adhesion of the fluorine-containing metal oxide layer 400 may be improved.

6(d) may be configured such that a metal oxide layer and a fluorine-containing metal oxide layer are sequentially formed on the substrate 20, but gradually transition from the metal oxide layer to the fluorine-containing metal oxide layer. In this case, by controlling the valves 33 and 53 and/or the suspension controller 60 of the storage units 30 and 50, plasma coating is performed by first supplying only the first slurry solution, and then gradually reducing the supply amount of the first slurry solution. By reducing the amount and increasing the supply amount of the second slurry solution, and finally supplying only the second slurry solution to perform plasma coating, the coating layer 500 that gradually transitions as described above may be formed.

In this way, by plasma coating two or more coating solutions individually or by mixing them by various coating methods, it is possible to increase adhesion to the substrate 20 and form a super-water-repellent surface with a low surface energy of the outermost surface on the substrate 20. .

Meanwhile, in one embodiment, the plasma coating process of step S30 is performed at room temperature and actual pressure, and a distance between the plasma generating unit 10 and the substrate 20 may be maintained between 2 cm and 20 cm, for example. In order to form the super water-repellent coating film according to the present invention, the surface temperature of the substrate 20 in the plasma spray coating step (S30) is preferably 500 degrees Celsius or more and 5000 degrees Celsius or less. And it is preferable that the thickness of the coating film coated by this step (S30) is 50 nm to 100 μm, and the surface roughness of the coating film is between 1 nm and 1 μm.

After forming the super water-repellent coating film on the surface of the substrate by the above-described coating film forming step (S30), a post-treatment step (S40) may be further performed if necessary. In one embodiment, the post-treatment step (S40) may include a firing process in which the coating film can more reliably adhere to the surface of the substrate 20. For example, the post-treatment step S40 according to an embodiment may include firing the substrate 20 for a time between 10 seconds and 60 minutes in a temperature environment between 500 degrees Celsius and 1000 degrees Celsius.

7 is a view for explaining the effect of the super water-repellent coating film formed according to an embodiment of the present invention. In the illustrated experiment, a microparticle slurry solution of F-SiO ₂ was coated on a substrate, and FIG. 7(a) is a photograph of the substrate with this coating film formed at 500 degrees Celsius for 10 minutes, 20 minutes, and 60 minutes. And Figure 7(b) is a photograph of a state left at 600 degrees Celsius for 10 minutes, 20 minutes, and 60 degrees. In the drawings, it was confirmed that the super-water-repellent coating film according to the present invention maintains super-water-repellent properties of 150 degrees or more at a contact angle of 500 degrees Celsius or higher, and thus can form a highly heat-resistant super water-repellent surface based on metal oxide surface treatment.

As such, those of ordinary skill in the field to which the present invention pertains will understand that various modifications and variations are possible from the description of this specification. Therefore, the scope of the present invention is limited to the described embodiments and should not be defined, and should be defined by the claims and equivalents to the claims to be described later.

10: plasma generator
15: suspension supply nozzle
30, 50: suspension reservoir
40: washing liquid storage unit
60: suspension controller

Claims (14)

As a high heat resistance super water repellent surface treatment method,
Performing a blasting treatment on the surface of the base material so that the surface of the base material has a predetermined range of roughness (S20); And
Forming a super-water-repellent coating film by spraying the coating solution on the surface of the substrate by means of suspension plasma spray coating (S30); includes,
The coating solution includes: (i) a slurry solution in which fine particles of metal oxide doped with one of fluorine (F), nitrogen (N), carbon (C), or silicon (Si) are dispersed in a solvent; Or (ii) a slurry solution in which metal oxide microparticles are dispersed in a solvent and metal oxide microparticles doped with one of fluorine (F), nitrogen (N), carbon (C), or silicon (Si) are dispersed in a solvent. Slurry solution; High heat resistance super water-repellent surface treatment method, characterized in that. The method of claim 1, wherein the metal oxide,
(i) an oxide of one of the elements capable of forming oxides from Group 1 to Group 16 elements;
(ii) an oxide of one of lanthanum and rare earth metals including scandium (Sc) and yttrium (Y);
(iii) an oxide of one of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and silicon (Si); And
(iv) Elements capable of forming oxides from the Group 1 to Group 16 elements, rare earth metals, magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and silicon ( An oxide of a composition consisting of two or more elements selected from the group consisting of Si); High heat resistance super water-repellent surface treatment method, characterized in that one of. The method of claim 1,
High heat resistance super water-repellent surface treatment method, characterized in that the solvent comprises at least one of water, ethanol, benzene, and toluene. The method of claim 1,
High heat resistance super water repellent surface treatment method, characterized in that the size of the metal oxide fine particles doped with one of fluorine (F), nitrogen (N), carbon (C), or silicon (Si) is 10 nm to 500 nm. The method of claim 1, wherein the step of forming the super water-repellent coating film (S30),
High heat-resistant candle comprising the step of coating a slurry solution of metal oxide fine particles doped with one of the fluorine (F), nitrogen (N), carbon (C), or silicon (Si) on the surface of the substrate Water-repellent surface treatment method. The method of claim 1, wherein the step of forming the super water-repellent coating film (S30),
A slurry solution of metal oxide microparticles coated with the slurry solution of the metal oxide microparticles on the surface of the substrate and doped with one of the fluorine (F), nitrogen (N), carbon (C), or silicon (Si) thereon High heat resistance super water-repellent surface treatment method comprising the step of coating. The method of claim 1, wherein the step of forming the super water-repellent coating film (S30),
Metal coated with a slurry solution of the metal oxide microparticles on the surface of a substrate, and doped with the metal oxide microparticles and one of the fluorine (F), nitrogen (N), carbon (C), or silicon (Si) Coating a mixed slurry solution of oxide fine particles, and coating a slurry solution of metal oxide fine particles doped with one of the fluorine (F), nitrogen (N), carbon (C), or silicon (Si) thereon. High heat resistance super water-repellent surface treatment method comprising a. The method according to any one of claims 5 to 7,
High heat resistance super water repellent surface treatment method, characterized in that the thickness of the coating film coated by the step of forming the super water repellent coating film (S30) is 50 nm to 100 μm. A suspension plasma thermal spray coating device that performs a high heat-resistant super water-repellent surface treatment on the surface of a substrate,
A first storage unit for storing a first coating solution;
A second storage unit for storing a second coating solution;
A plasma generator for generating a plasma jet;
A suspension controller having a function of sequentially supplying or mixing at least one of the first coating solution and the second coating solution; And
Including; a nozzle for spraying the coating solution discharged from the suspension controller to the outlet side of the plasma generating unit,
The first coating solution is a slurry solution in which metal oxide fine particles are dispersed in a solvent,
The second coating solution is a slurry solution in which metal oxide microparticles doped with one of fluorine (F), nitrogen (N), carbon (C), or silicon (Si) are dispersed in a solvent. Thermal spray coating device. The method of claim 9,
The suspension plasma spray coating apparatus, characterized in that the size of the metal oxide fine particles doped with one of fluorine (F), nitrogen (N), carbon (C), or silicon (Si) is 10 nm to 500 nm. The method of claim 9,
Suspension plasma spray coating apparatus, characterized in that the operation to coat the first coating solution on the surface of the substrate and the second coating solution thereon. The method of claim 9,
Suspension plasma spray coating apparatus coats the first coating solution on the surface of the substrate, coats the mixed solution of the first coating solution and the second coating solution thereon, and coats the second coating solution thereon Suspension plasma thermal spray coating device, characterized in that it operates to operate. The method of claim 9,
And the nozzle is disposed in the cathode of the plasma generating unit in a coaxial manner with the cathode to spray the first or second coating solution toward the outlet of the plasma generating unit. The method of claim 9,
The nozzle comprises a nozzle cap coupled to the outlet side of the plasma generator,
The nozzle cap has a predetermined thickness in the spraying direction of the plasma jet and has a disk shape with an empty space therein, and a through hole is formed in the center so that the plasma jet penetrates, and at least one spray hole is formed on an inner peripheral surface surrounding the through hole. And the first or second coating solution is filled in the inner space of the nozzle cap and then sprayed through the spray hole.

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