KR20200120808A - Method for forming nano-inorganic film - Google Patents

Abstract

The present invention relates to a method for using a high-functional nano-inorganic composition to form a nano-size thin film. The present invention relates to a nano-inorganic coating technology using the high-functional nano-inorganic composition which exhibits excellent mechanical characteristics mainly including surface strength and wear resistance; which has very stable chemical characteristics such as water resistance, acid resistance, and alkali resistance; and which is formed of inorganic materials to provide excellent thermal stability. Moreover, functions, such as ultra-hydrophilic, hydrophilic, and hydrophobic characteristics can be controlled depending on coating methods, and a surface may have excellent contamination resistance and easy-clean characteristics and excellent optical characteristics such as light transmissivity and reflectivity, due to thin-film coating. The method comprises a pretreatment step, a coating step, a drying step, and a sintering step.

Description

Method for forming nano-inorganic film {Method for forming nano-inorganic film}

The present invention relates to a method for forming a fine-sized thin film using a high-functional nano-inorganic composition. The above high functionality is mainly a nano-inorganic coating that has excellent mechanical properties including surface hardness and abrasion properties, has very chemically stable properties such as water resistance, acid resistance, and alkali resistance, and is composed of inorganic materials and has very excellent thermal stability properties. It's technology. In addition, depending on the coating method, it is possible to control functions of super-hydrophilic, hydrophilic, and hydrophobic characteristics, and the thin-film coating provides excellent surface contamination and easy-clean characteristics, and optically superior characteristics in terms of light transmittance and light reflectance. Have.

Nano coating technology has been mainly used to form a thin film with a height of nanometer thickness that is coated using expensive equipment such as CVD or sputtering in very precise technical fields such as semiconductors and displays. However, with the recent development of nanomaterials, research and development are in progress to enable nanometer-thick coating through general coating methods.

In particular, in the case of the recently developed FC coating agent of Welcher Finetech, nano-thickness is achieved through general spray coating, spin coating, bar coating, slot die coating, sponge, brush, brush, etc. using a material consisting of several nanometers to tens of nanoparticles. Coating is described with respect to a method of forming an inorganic coating composition and an inorganic coating film through Korean Patent No. 10-1735383.

However, in the case of the nano-inorganic material shown in the prior art of the above patent, the amount of solid content is made up of tens of wt% or more and is coated with a thickness of several hundred to several thousand nanometers. Thus, whitening occurs during coating through a general coating method, and microscopic It can be seen that a problem such as cracking occurs, and a smooth coating with a coating thickness of several tens of nanometers is difficult due to an excessive solid content.

In particular, when the coating thickness is thick, defects inside the coating layer and the formation of an air layer during the heat treatment process are easy, so that durability through such defect areas rapidly decreases. In addition, it can be seen that there are many differences in various functional parts when the coating film is formed with the material through the above patent.

Korean Patent Registration No. 10-1735383 Korean Patent Registration No. 10-1414019

In order to solve the conventional problems as described above, in the present invention, it is an object of the present invention to form a nano-inorganic coating film having very high smoothness at the level of several tens of nanometers or hundreds of nanometers and having no defects in the coating film.

To this end, the amount of solid content contained in the composition is lowered to 10 wt% or less, and the amount of water, which is a solvent, is increased correspondingly, so that a nano-coating film can be easily formed by a general coating (film formation) method, and a very uniform film can be formed. It was intended to solve the problems of the existing invention by reducing the whitening phenomenon occurring during formation and securing higher durability.

In addition, when the thickness is lowered to the level of tens to hundreds of nanometers as described above and high smoothness is maintained, optical properties such as light transmission and light reflection are more than twice as high, and the whitening phenomenon caused by elution of metal oxides can be solved.

As a means for solving the above problems, the nano-inorganic composition,

At least one of sodium oxide (Na ₂ O), potassium oxide (K ₂ O), and lithium oxide (Li ₂ O), which is an alkali metal oxide (M ₂ O) represented by the following formula, is included; Inorganic acid compounds; And water (H ₂ O);

, 실리카의 몰수인

, n은 1 ~ 20의 자연수;In the following formula, the number of moles of alkali metal oxides

, Which is the number of moles of silica

, n is a natural number from 1 to 20;

[Chemical Formula]

In 100 parts by weight of the nano-inorganic composition of the above formula, (M ₂ O+ySiO ₂ ) is 0.1 to 10 parts by weight, and is prepared by including 0.01 to 2 parts by weight of the inorganic acid compound and the rest of water.

By reducing the thickness of the coating film from tens of nanometers to several hundreds of nanometers by using the prepared nano-inorganic composition, the formation of the air layer in the coating film is reduced, and the temperature is increased by lowering the first heat treatment (drying) temperature from 110°C to 90°C. It was intended to improve durability by reducing defects by preventing the formation of an air layer due to vaporization of water according to.

In addition, various coating methods can be used as a means for solving the above problems. In the present invention, in the case of transparent substrates such as glass, it was found through experiments that coating by using a slot die and bar coating method is the most uniform and easy to coat at the level of tens of nanometers, and the matte or gloss effect of the base material to be coated is realized. For the base material that needs translucency or opacity through haze, it can be seen that the use of spray coating is the most effective means.

The inorganic coating film formed by using the above-described nano-inorganic composition according to the present invention is excellent regardless of the type of the base material, in particular, the bonding strength with the surfaces of the metal material and the non-metal material is strong. There is no problem that the coating film is separated from the base material.

In addition, the inorganic coating film is a hydrophilic coating film, which has weak bonding strength with organic substances, so that organic contaminants are not well adhered to it. Furthermore, it is easy to remove organic substances as well as other contaminants, so that only water flows on the surface of the coating film without any other work. It has the effect of easily removing contaminants.

In addition, due to the characteristics of the inorganic coating film, a nano-inorganic composition having excellent weather resistance, durability, chemical resistance, abrasion resistance, high hardness of the surface, far infrared radiation, non-flammability, chemical resistance, corrosion resistance, and antibacterial properties, and an inorganic coating film using the same are provided.

In addition, since water is used as a solvent, contaminants are not generated during the manufacturing process and coating process of the composition, so it is eco-friendly, and its lifespan is semi-permanent.

1 is a diagram showing the formation of a bar and slot die coating film according to the present invention
2 is a light transmission characteristic according to the coating film formation of the present invention
3 is a light reflection characteristic according to the coating film formation of the present invention
4 is an example of forming a coating film by spraying of the present invention
5 is a triangular analysis diagram of the composition according to the present invention
6 is a haze embodiment according to the present invention
7 is a contact angle embodiment according to the present invention
8 is a readability example according to the present invention
9 is a thickness measurement diagram according to the present invention
10 is an Example of the characteristics of Easy-Clean of the present invention

Hereinafter, the nano-inorganic composition of the present invention and a method of manufacturing the same will be described in detail.

The nano-inorganic composition of the present invention,

At least one of sodium oxide (Na ₂ O), potassium oxide (K ₂ O), lithium oxide (Li ₂ O), which is an alkali metal oxide (M ₂ O) represented by the following formula, is selected; Inorganic acid compounds; And water (H ₂ O);

고, x1, x2, x3 및 y 는 각각 0.01 ~ 500, n은 1 ~ 20의 자연수이며, 실리카의 몰수인

며;In the following formula, the number of moles of alkali metal oxides

High, x1, x2, x3 and y are each 0.01 ~ 500, n is a natural number of 1 ~ 20, the number of moles of silica

And;

[Chemical Formula]

In 100 parts by weight of the nano-inorganic composition of the above formula, (M ₂ O+ySiO ₂ ) is 0.1 to 10 parts by weight, and is prepared by including 0.01 to 2 parts by weight of the inorganic acid compound and the rest of water.

The composition represented by the above formula may additionally contain a dispersant, a catalyst, and a surfactant, depending on the required functionality, coating method, and coating device.

The change of the composition according to the above coating device may vary depending on the pretreatment equipment, and in particular, a dispersant is used to improve adhesion properties by including a surfactant depending on whether the surface of the base material is hydrophilic, and to improve the dispersion of color pigments for color. It may further include, and may further include a catalyst for shortening the production time of the composition and promoting chemical reactions.

The amount of the added solvent (water + inorganic oxide compound) is greater than the solubility of the alkali metal oxide added in the solvent, and phosphoric acid or boric acid is mainly used as the inorganic acid compound.

The nano-inorganic composition of the present invention may be prepared by including one or two and all three of x ₁ Na ₂ O, x ₂ K ₂ O, and x ₃ Li ₂ O represented by the above formula. That is, the present invention includes at least one of the alkali metal oxides represented in the above formula, thereby improving the adhesion or adhesion to the base material while improving the easy-clean properties, antifouling properties, water resistance, and mechanical and chemical properties of the coating thin film. It is possible to implement a nano-inorganic composition that improves various high functionality including.

를 만족하여야 하며, 산화나트륨(Na₂O)의 몰수 x₁, 산화칼륨(K₂O)의 몰수 x₂, 산화리튬(Li₂O)의 몰수 x₃중에서 상기 X(X=x₁+x₂+x₃)는 항상 0보다 큰 수로서 X〉0를 만족하며, 각각의 알칼리 산화금속들은 0보다 크거나 같은 수로서

와 같이 표현할 수 있다. In the above formula of the present invention, X is the number of moles of alkali metal oxides (M ₂ O) contained in the nano-inorganic composition, and y is the number of moles of silica (SiO ₂ ), and the number of moles of silica is always greater than or equal to the number of moles of alkali metal.

X (X=x ₁ +x) in the number of moles of sodium oxide (Na ₂ O) x ₁ , the number of moles of potassium oxide (K ₂ O) x ₂ , and the number of moles of lithium oxide (Li ₂ O) x _{3 2} +x ₃ ) is always a number greater than 0, satisfying X>0, and each alkali metal oxide is a number greater than or equal to 0

It can be expressed as

와 같이 Na₂O를 50% 이상 포함하는 나노무기조성물로 제조 되어 도막두께가 일정 이상이 될 경우 도1과 도8에 관찰되는 것처럼 백화현상의 원인이 되고 소성시 공기층을 발생시키는 원인이 되는 물질로서 본 발명의 제조예 4와 제조예 5를 통하여

의 식을 만족시킬 수 있도록 제조할 경우 광학특성, 친수특성 및 내수성(내구성)에서 만족스러운 결과가 나타났으며 Na₂O의 최적의 함량은 X(X=x₁+x₂+x₃)와 대비하여 30±10% 임을 실시예를 통하여 알 수 있었다.Also in the existing invention

As shown in Figs. 1 and 8, when the film thickness is made of a nano-inorganic composition containing 50% or more of Na ₂ O, as shown in Figs. 1 and 8, it causes whitening and creates an air layer during firing. As through Preparation Example 4 and Preparation Example 5 of the present invention

When manufactured to satisfy the formula, satisfactory results were found in terms of optical properties, hydrophilic properties, and water resistance (durability), and the optimal content of Na ₂ O was X(X=x ₁ +x ₂ +x ₃ ) and In contrast, it was found through the examples that it was 30±10%.

In addition, in the embodiment, in order to mix the alkali metal oxide, the molar ratio (y/X) of the alkali metal oxide and the silica is most stable in 3 to 4, and it can be seen that the whitening phenomenon is strong and water resistance and heat resistance are obtained.

The ratio of the solid content (M ₂ O + ySiO ₂ ) and the solvent (water + inorganic oxide compound) of the nano-inorganic composition was shown in Preparation Examples 4 and 5, where the optical properties and durability properties were greatly improved when the solid content was 10 wt% or less. This can be seen through an example.

In particular, in the case of a solvent (water + inorganic oxide compound), phosphoric acid and boric acid can be included according to the required properties, and when 2% or more is added, the gel is formed and does not meet the properties of the required nano-inorganic composition.

The nano-inorganic composition ((x ₁ Na ₂ O+x ₂ K ₂ O+x ₃ Li ₂ O)·ySiO ₂ ), as shown in the formula, is substituted with other non-metallic elements in the central metal atom to form silicon (Si) and A single bond between other atoms is formed into a double bond, and a network structure is created, and a condensation reaction with the silicate causes the hydroxide ions (-OH) attached to the silicate to be replaced and dissociated with other ions. It is expected to be a mechanism to improve water resistance by preventing it.

In addition, it was intended to optimize the required functionality by directly controlling the content of the metal oxide added according to the different characteristics of each metal oxide including the volume change of the metal oxide or according to the required functionality.

In addition, when the pH of the nano-inorganic composition is 11 or less, solidification proceeds, making it difficult to manufacture, and when the pH of the nano-inorganic composition is 13 or more, various functionalities are reduced, and a PH between 11 and 13 is most suitable.

In addition, the contact angle of the surface of the thin film of the nano-inorganic composition exhibits a hydrophilic property of 20° or less and has an Easy-Clean property.

In addition, the above nano-inorganic composition can control haze (turbidity) to make glossiness or matte form, and in the case of transparent substrates, it can satisfy consumer's needs by implementing various haze (turbidity) such as translucency and opacity. have.

In the present invention, scattering degree, haze, and turbidity have the same meaning and represent a transparent state that varies depending on the transparency of the transparent substrate, and may be used as a meaning representing the glossiness of the coated surface, such as a glossy or matte lamp.

In the present invention, when a coating film is formed on a transparent substrate such as glass using the above nano-inorganic composition, as in general clear and clean glass, the light transmittance is 80% or more without haze. Steps, 60% transmittance in 3 haze steps, 50% transmittance in 4 haze steps, 40% transmittance in 5 haze steps, 30% transmittance in 6 haze steps, 20% transmittance in 7 haze steps, 10% If the transmittance is defined as 8 levels of haze and 9 levels of haze as complete opacity, a coating thin film can be formed over all areas from haze 1 to 9 haze. As such, ions with different hydroxide ions (-OH) attached to silicate can be formed. As it is substituted and dissociated, it is expected to be a mechanism to improve water resistance by preventing the penetration of water.

[Example]

[Example]

The nano-inorganic composition according to the present invention was prepared as follows.

Preparation Examples 1 to 5 are prepared by the same method and will be described using Preparation Example 4, which is judged to be the most suitable as a Preparation Example of the present invention. In order to prepare 200 g of the nano-inorganic composition, as shown in Preparation Example 4, ySiO ₂ : 0.105 mol and X(x1+x2+x3) M ₂ O: 0.027 mol respectively x ₁ : 33.8%, x ₂ : 33.8% x ₃ : Mix uniformly so as to have a fraction of 26.5%, or use silica (SiO ₂ ) for sodium silicate, potassium silicate, and lithium silicate, respectively, to be uniformly prepared so that the molar fraction may be the molar ratio of the solids contained in the composition of the present invention ( Mixing the first composition prepared by controlling y/x) to 3.885 and the solid content is 4.04 wt% and the second composition prepared 190.72 g of water (H ₂ O) and 1.2 g of inorganic oxide (phosphoric acid or boric acid) Thus, 200 g of the final nano-inorganic composition of the present invention is prepared. Unlike the manufacturing process of a two-component nano-inorganic composition in which the first composition and the second composition are respectively prepared and mixed, in the process of preparing the first composition, the second composition is mixed with each component. By adding appropriately, a one-pack type nano-inorganic composition can be prepared.

In addition, Preparation Examples 1, 2, 3 and 5 are the molar ratios of alkali metal oxide (M ₂ O) and silica (SiO ₂ ) and each alkali metal oxide (x _1, x ₂ ) as shown in [Table 1] below. _The composition was prepared in the same manner as in Preparation Example 4 by varying the mole fraction of _, x ₃ ).

200g manufacturing division Manufacturing Example 1
(Part by weight) Manufacturing Example 2
(Part by weight) Manufacturing Example 3
(Part by weight) Manufacturing Example 4
(Part by weight) Manufacturing Example 5
(Parts by weight) G
Solid content



ySiO ₂ (molar number) 0.3327 0.3216 0.3206 0.105 0.206 x1+x2+x3 (for moles) 0.0916 0.0847 0.0818 0.027 0.051 M ₂ O mole fraction Na ₂ O 0.5151 0.416 0.417 0.338 0.28 K ₂ O 0.3031 0.334 0.214 0.397 0.38 Li ₂ O 0.1818 0.25 0.369 0.265 0.34 Sum of mole fractions One One One One One Molar ratio (y/x) 3.63 3.7968 3.9213 3.885 4.0179 Solid content wt% (M ₂ O+SiO ₂ ) 13.01 12.4 11.96 4.04 7.8 menstruum H ₂ O 186.39 186.6 187.14 194.76 191.6 Inorganic oxide compound
(Phosphoric acid or boric acid) 0.6 One 0.9 1.2 0.6 Sum 186.99 187.6 188.04 195.96 192.2 Total (solid + solvent) 200 200 200 200 200

division Manufacturing Example 1 Manufacturing Example 2 Manufacturing Example 3 Manufacturing Example 4 Manufacturing Example 5 Pencil hardness 9H 9H 9H 9H 9H Adhesion 5B 5B 5B 5B 5B Easy Clean Castle ◎ ◎ ◎ ◎ ◎ Light transmittance Improvement within 1% Improvement within 1% 1% or more improvement 2% or more improvement 2% or more improvement Contact angle 23.2
Hydrophilic 20.7
Hydrophilic 12.4
Hydrophilic 7.8
Super hydrophilic 9.3
Super hydrophilic Water resistance ○ ○ ○ ◎ ◎

The composition represented by the above formula may additionally contain a dispersant, a catalyst, and a surfactant, depending on the required functionality, coating method, and coating device.

As the base material used in the present invention, various materials such as metal and non-ferrous metal materials, other plastics (polymer materials), films, ceramics, tiles, stone materials, and wood can be used, and various base materials requiring coating of other paints are all available. .

Looking at the process of forming a coating film using the prepared composition, the step (S200) of pre-treating (washing) the base material requiring coating is very important following the step (S100) of preparing the composition of the above formula. Cleaning is a very important process because any foreign substance on the surface can cause defects in order to coat the nano-inorganic composition, and it can be cleaned with a general alkali or neutral detergent, and if necessary, use a substance such as alcohol or acetone or pickling. It can be cleaned by using the same.

In addition, cleaning may be performed as a pretreatment prior to coating using a method such as polishing.

In particular, in the case of transparent substrates, defects caused by foreign substances remaining on the base material are an important process because they can have a very large effect on the quality after forming the coating film.

After washing is finished, a drying step (S300) for removing water or moisture formed on the surface is performed, and then a coating composition attaching step (S400) of attaching the above-described nano-inorganic composition is performed using various coating methods. Foreign substances may remain in the water or other media used during cleaning, and these foreign substances may remain on the surface as they are dried. To remove them, it is necessary to cleanly dry the surface using air (wind) or heat. When using a high temperature, use water such as distilled water or other high-purity substances to prevent foreign substances from being left on the coating surface.

As described above, after the drying step (S300) and the coating composition attaching step (S400) is finished, it is necessary to dry or fire the coated surface again. If you heat a high temperature of 100℃ or higher for sintering immediately after the coating composition is attached, most of the water contained in the composition may evaporate and cause problems such as air bubbles. A step of drying time (S500) is required. In order to secure the durability of the coating after this drying time and successively, a firing step (S600) for heat treatment at 100 to 1000°C is required. The firing step (S600) is connected to the drying step (S500) and continuously controlled using a temperature controller.

In general, the heat treatment process is performed at less than 300°C, but in the case of a base material having a particularly high use temperature or a base material used in a very poor environment, the heat treatment may be performed at 500°C or higher.

If heat treatment is required at 700° C. or higher like tempered glass, S600 may be replaced by a process of performing heat treatment for strengthening the glass immediately in step S500, which is the drying step.

Since the composition of the present invention is composed of a complete inorganic material, there is a phenomenon that the durability increases when heat treatment is performed at a high temperature in general, and in a very good environment where temperature and humidity are controlled, such as in the room where we live daily, the S500 process It can be used later.

The sintering for heat treatment uses heat (temperature) energy for the adhesion between the coated composition and the base material. Ultraviolet rays, infrared rays, microwaves, etc. can be used, and as natural curing, it can be hardened at room temperature and attached. However, if curing is performed at room temperature, a little more time is consumed, and in terms of functionality such as durability, it may be slightly inferior compared to the case of heat treatment.

The heat treatment time requires a heat treatment (firing) holding time of 10 minutes or more excluding the temperature rise time. In addition, even in the case of cooling after firing, it is necessary to allow sufficient cooling time when coating a very sensitive base material such as glass or stone. If high-temperature heat treatment is performed, it may come out to the outside of the natural state at room temperature below 100℃. It is good to have it. In particular, when coating on a material sensitive to cooling temperature such as glass and stone, a cooling step (S700) of forcibly controlling the cooling time may be required as needed.

More specifically, the process of forming the coating film is described, following the step of preparing the composition of the above formula (S100), the step of pretreating (washing) the base material requiring coating (S200) is generally the surface of the base material for coating. In the process of processing, since it contains a lot of foreign substances such as organic matter and oil, in order to remove it, water washing is generally performed, which is wet washing, and if the water washing environment is difficult, dry washing is performed using a method such as plasma.

Compared to water cleaning, which is wet cleaning, dry cleaning is relatively simple in process and has advantages such as hydrophilizing the surface of the base material for forming a coating film, and in some cases, surface treatment is required to facilitate adhesion of the base material and the nano-inorganic composition. When there is, the plasma process is very beneficial, but there is a drawback that foreign substances may ultimately remain on the surface of the base material, so it is necessary to select a cleaning method that can completely remove foreign substances from the surface depending on the base material.

For cleaning, a cleaning agent can be used to remove foreign substances from the surface, and after using the cleaning agent, it must be completely removed using air or the like so that surfactants or foreign substances in the cleaning agent do not remain on the surface.

Also, depending on the surface roughness of the base material or the state of foreign substances attached to the base material, the base material surface can be polished or polished. This can be used for the purpose of improving the smoothness of the coated base material, when the surface is severely contaminated or when cleaning is difficult due to foreign matters permeating the base material.

On the other hand, before forming the inorganic coating film using the nano-inorganic composition of the present invention, the nano-inorganic composition of the present invention uses water as a solvent, so that the plasma has a hydrophilic property for the purpose of facilitating adhesion to the base material, Anodizing, sanding, etching, or the like may be further included so that the inorganic coating layer can be formed more efficiently.

In the ultrasonic cleaning, which can be used as one of the processes of cleaning the surface of the base material, after the base material is immersed in an ultrasonic tank, ultrasonic waves are generated so that even a fine part of the surface of the base material can be cleaned. It is preferable that the ultrasonic wave is 28 to 48 kHZ. In the ultrasonic cleaning process, a water-soluble cleaning agent containing an inorganic salt may be used. If a water-soluble detergent containing an inorganic salt is used, there is also an advantage of increasing the adhesion with the inorganic coating film, which is a coating film formed on the surface of the base material.

In addition, in the present invention, prior to the ultrasonic cleaning process, a deposition and steam cleaning step of removing oil and impurities may be further included. This is not necessary to proceed separately when the base material surface is clean, but when impurities are difficult to be removed, for example, it can be particularly preferably applied in the case of wood or stone.

The immersion and steam washing step is performed to remove various oils such as mineral synthetic oil adhering to the surface of the base material, and wash the base material by immersing it in a solvent or evaporate the solvent to condense the vapor on the surface of the base material. Let it flow and clean the oil and impurities by flowing condensed water. Washing by condensation of steam is dried immediately after it is taken out of the tank, so it is possible to move to the next step without going through a separate drying step, thereby shortening the production time.

In addition, after the cleaning is finished, a drying step (S300) is performed to remove water or moisture formed on the surface. When drying is performed using air or heat, it may be dried using air preheated to a predetermined temperature.

This is a process of removing moisture from the surface of the base material, and can be used after removing moisture from the air in summer, but when the ambient temperature is low and humidity is low, such as in winter, the air can be preheated to a temperature of about 50±20°C. At this time, by using the temperature above room temperature transferred to the surface of the base material, in the case of a transparent material when coating, a haze can be given or the glossiness of an opaque substrate can be selectively applied, such as glossy or matte, and a nano-inorganic composition can be efficiently coated. .

Of course, in order to intentionally implement the above oil, matte or haze (turbidity) without using preheated air, the desired degree of haze (turbidity) can be achieved by shifting the base material surface temperature above room temperature. The higher the level of haze (turbidity) is.

When the surface pretreatment and preheat drying treatment of the base material are finished, a coating step (S400) for attaching the nano-inorganic composition to the surface of the base material is performed.

The coating method of the composition is not particularly limited, and a known method may be used, for example, dipping coating or spray coating, roll coating, spin coating, bar coating, flow coating, curtain coating, knife coating, Vacuum deposition, ion plating, plasma deposition, sputtering, screen printing, brushing, sponge, brush, and other methods such as applying with a soft cloth, etc., or by using one or more methods simultaneously Nano inorganic composition can be coated.

At this time, it is preferable that the coating film of the nano-inorganic composition coated on the surface of the base material is coated to a thickness of 10 nm to 5 μm. All of the above coating methods may be controlled by the coating thickness within the above range depending on the application.

In some cases, in the coating step, chemical stability such as corrosion resistance and mechanical properties may be improved by increasing the thickness of the coating film by performing the process of S600 in S200 or S300 several times or more.

After coating the nano-inorganic composition on the surface of the base material by the above step, firing at a predetermined temperature for a predetermined time in order to completely cure the nano-inorganic composition (S600) is performed.

In the firing step (S600) of the dried base material, firing at a temperature of 100°C to 1000°C for 10 minutes to 3 hours is different depending on the type of base material, but the hardness and hardness of the coating film and the It is preferable for realizing a smooth surface roughness. The general firing temperature is heat treated at less than 300℃, but when the coated base material is used in a particularly harsh environment (exposed to water, salt water, strong acid, etc.), fire at 500℃ or higher or sufficiently heat treatment for more than 3 hours to ensure water resistance and durability. Can increase.

The firing step may be divided into a first drying process (S500), a second firing process (S600), and a cooling process (S700).

Specifically, first, the base material on which the coating film is formed is put into a sintering furnace, and the temperature inside the sintering furnace is gradually increased to about 3 to 5°C/min. When the temperature inside the kiln reaches the first firing temperature (100±20°C), the temperature is not increased any more, and the first firing process is performed for a predetermined time while maintaining the inside temperature of the kiln at the first firing temperature. At this time, the first firing temperature is preferably 100±20°C.

Since water is used as a solvent for the nano-inorganic composition of the present invention, the purpose of the first firing as described above is to rapidly increase the temperature at too high a temperature of 100°C or higher, or water as a solvent to the environment above 100°C. When exposed, the water constituting the nano-inorganic composition evaporates and the air layer is formed as shown in Fig. 1 due to the evaporation of water on the coating film, or defects may occur in the heat treatment process. Heat treatment is performed by releasing water present on the nano-inorganic composition to the outside by performing the first firing process of about a few minutes to several tens of minutes at about ±20°C.

Then, when the first firing process is completed, the temperature inside the firing furnace is gradually increased again. When the inside temperature of the kiln reaches the second firing temperature, the temperature is not increased any more and the secondary firing process is performed for a predetermined time while maintaining the inside temperature of the kiln at the second firing temperature. At this time, the second firing temperature is preferably 100 ℃ ~ 1000 ℃. If the temperature rises above 1000℃, the nano-inorganic composition does not cause physical and chemical problems even at temperatures above 1000℃, but most of the materials may cause deterioration due to heat (temperature), so carefully examine the temperature characteristics of the base material. You need to proceed.

In this way, when the first and second firing processes are completed, a cooling process (S700) of cooling the fired base material to room temperature is performed. In this cooling process, the base material is not treated specially, but the temperature of the base material is lowered to room temperature. At this time, the cooling process may be lowered while controlling the temperature at a constant rate, or may be performed so that it can be cooled naturally, as in the first and second firing processes.

It goes without saying that the firing temperature may be differently selected to reduce thermal shock due to cooling since there is a difference in thermal expansion characteristics between the base material and the coating film depending on the material of the base material.

In particular, in the case of a base material that is very sensitive to temperature such as glass or stone, if it is directly exposed to room temperature above 100°C, defects such as micro cracks or breakage may occur on the surface, so care is required according to the base material.

It will be described through examples using different coating methods depending on the base material for forming a coating film using the nano-inorganic composition of the present invention.

In the case of a base material mainly made of a plate material such as steel, glass, stone, wood, etc., spray or bar coating method is the most common, and it may be most suitable for automation for mass production.

In addition, this can be achieved by controlling the height, flow rate, moving speed, solid content, air pressure, etc. of the nozzle in order to form a coating film with an optimum thickness.

As the height of the nozzle increases, the amount of composition adhered to the base material surface per unit area decreases and the coating thickness decreases. Conversely, as the height of the nozzle decreases, the amount of composition adhered to the base material increases, resulting in an increase in the coating thickness. It is a natural physical law that as the speed increases, the amount of the attached composition decreases, and as the movement speed decreases, the amount of the attached composition increases. In addition, when the solid content is low, the coating thickness decreases, and when the solid content is high, the coating thickness becomes thick. Surface turbidity can also be controlled by controlling the air pressure to be ejected from the composition.

In addition, it is natural that the state and thickness of the coating film can be controlled by directly controlling the flow rate of the composition.

After performing the cleaning (S200) step for pretreatment of the above plate, the height of the nozzle is 100mm, the flow rate is 1,000ul/min, the movement speed of the base material is 0.25m/min, and the movement speed of the nozzle is 20m/min for an area of 100*100mm. At this time, based on the ambient temperature of 25±5℃ and humidity of 40-60%, the coating film can be formed with a thickness of about 200-500nm, and it is possible to increase the number of coatings under the same conditions to increase the coating thickness.

In the present invention, the unit area represents 100*100mm.

The above standards are controlled so that the thickness of the coating film and the surface condition of the coating film remain uniform and constant by increasing the flow rate when the humidity is less than 40% and decreasing the flow rate when the humidity is more than 60%, and absorbs water like stone or wood. In the case of having a surface to be coated, the most optimal thickness of the coating film should be formed by increasing the flow rate in consideration of this.

When the embodiment through the spray method is described in detail, it is as follows.

In the case of forming a coating film based on the coating film thickness, the spray-type coating example is carried out using the following calculation formula.

The relational expression of the conditions for forming a spray-type coating film is as follows.

H _t : coating thickness

Q: Flow rate (ul/min)

C: viscosity or concentration (solid content)

U: moving speed of base material (m/min)

t: number of coatings

W: spray area (m2)

h: height of the nozzle (m)

In the case of 0.1mx 0.1m flat coating, flow rate (100 ul/min ~ 10,000 ul/min), viscosity (1~10cp), moving speed of base material (0.1~5m/min), moving speed of nozzle (10~50m/ min), the height of the nozzle (0.05 ~ 1m), it is possible to create a coating layer of various thicknesses through conditions such as the number of coatings. In the above equation, the air pressure for controlling the flow rate is determined based on a constant value as a static pressure, and coating is performed.If it is 0.5 MPa or more, haze (turbidity) may occur in the case of transparent glass, and in the case of an opaque base material, the transmittance is lowered to make it translucent or opaque. I can.

In the present invention, when a coating film is formed on a transparent substrate such as glass using the above nano-inorganic composition, as in general clear and clean glass, the light transmittance is 80% or more without haze. Steps, 60% transmittance in 3 haze steps, 50% transmittance in 4 haze steps, 40% transmittance in 5 haze steps, 30% transmittance in 6 haze steps, 20% transmittance in 7 haze steps, 10% If the transmittance is defined as 8 stages of haze and 9 stages of haze as complete opacity, a coating thin film can be formed over the entire area from Haze 1 to Haze 9 stages.

The following equation is a proportional equation related to the above scattering degree (haze).

S : Scattering degree at constant flow rate (haze or turbidity)

C: viscosity or concentration (solid content)

P: air pressure

U: moving speed of base material (m/min)

T: surface temperature of the base material

t: number of coatings

W: spray area

h: height of the nozzle

In the case of 0.1mx 0.1m flat glass coating, the ambient temperature is 25±5℃ and the humidity is 40~60%. If the surface temperature of the base material is also assumed to be room temperature, air pressure (0.1Mpa ~ 1Mpa), viscosity (1~10cp) , The base material movement speed (0.1~5m/min), the nozzle movement speed (10~50m/min), the nozzle height (0.1~0.5m), and various haze (turbidity) I can. Under the above conditions, if the flow rate is more than a certain amount (e.g., 3,000 ul/min or more), it may become transparent again, so precise control is required. It can be seen that this viscosity or concentration is also proportional to the scattering degree.

When the base material is glass, the spray coating method is suitable as a coating method for haze, but for coating in a clear and clean glass state, the slot die or bar coating method is advantageous because it can maintain a certain surface roughness compared to the spray method coating.

In addition, in order to control haze, it is possible by controlling the temperature of the base material surface or by controlling the surrounding environment (temperature and humidity).

That is, as the surface temperature of the base material is increased above room temperature, the scattering degree (haze or turbidity) can be increased under the same conditions, and the same effect can be achieved by increasing the ambient temperature. However, it is easy to use the slot die or bar coating method described above because it is difficult to control by spray method in order to preserve the clear characteristics of glass.

The slot die or bar coating method is to attach the composition to the coated surface by forming a meniscus by separating the slot and the bar from the surface to be coated by tens to hundreds of micrometers.Examples are as follows. For this, when considering a 100nm-thick coating layer based on a 100mm x 100mm glass sample, the height of the bar or slot die is separated by about 100±50㎛, and the flow rate injected into the bar or slot is 50~500ul/min. , Proceed at the moving speed of the base material 1~10 mm/sec. At this time, the thickness of the coating film can be adjusted by controlling the height, flow rate, moving speed, solid content of the composition, and the like of the bar or slot die.

The relational expression of conditions for bar or slot die coating is as follows.

: 바의 길이

: The length of the bar

: 매니스커스 끝단에서 실제 코팅이 되어지는 두께

: Thickness that is actually coated at the end of the meniscus

: 모재의 이동속도

: Base material movement speed

: 유량 (코팅 시 매니스커스에서 소모되는 용액의 양)

: Flow rate (amount of solution consumed in the meniscus during coating)

: 용액 주입용 주사기 니들의 개수

: Number of syringe needles for solution injection

: 매니스커스의 곡률반경

: Curvature radius of meniscus

: 표면장력

: Surface tension

: 용액의 점도

: Viscosity of solution

: 바의 높이

: Bar height

t _dry : thickness of the film after drying

Assuming that the amount of solution consumed in the meniscus and the amount newly injected during coating are the same, it can be expressed by the following equation,

If the number of needles to inject the composition to be added as the coating area increases, it can be expressed by the following equation.

: 주사기의 내경

: Inner diameter of syringe

: 조성물 주입 속도

: Composition injection rate

Using the following equation according to Landau Levich theory,

,

,

이고, 상기의 식을 응용하면

임으로 최종적으로 아래의 식을 유추할 수 있다.here

And applying the above equation

Finally, the following equation can be inferred.

In other words, it can be seen that T _wet , which is the actual coating thickness at the end of the meniscus, is proportional to the number and flow rate of the needle, and is inversely proportional to the length of the bar and the injection rate of the composition, and C ₁ is a constant related to the dynamic meniscus curvature. .

Unlike spray coating, in the case of bar or slot die coating, it is not easy to increase the thickness more than twice under conditions excluding solid content. On the other hand, as a coating method for improving transmittance among optical properties, a bar or slot die coating capable of realizing a relatively uniform surface with a thin film thickness is easier.

When the coating step (S400) for attaching the nano-inorganic composition is finished as described above, the firing step is performed.

As described above, firing is performed by being divided into primary and secondary, and firing can be performed without distinction between primary and secondary depending on the base material, and the firing temperature can also be adjusted.

For example, it is more effective to heat treatment only on the surface where the coating film is formed rather than heat-treating the entire base material by putting the base material inside the kiln according to the temperature-sensitive film or the base material such as stone or wood. Alternatively, it can be carried out in a manner that heat treatment is performed only on the surface of the base material using infrared (medium infrared) or the like.

For another purpose, if a method such as roll coating, spray coating or dipping coating is used depending on the type of film and substrate made of polymer material, single-sided or double-sided coating is possible. By firing using microwave, it is possible to coat polymeric materials with various sizes of thickness, so that various properties of inorganic materials can be utilized while maintaining various shapes, so that the scope of application can be diversified by attaching directly to industrial materials already installed. have.

1. Pencil hardness

It was measured according to the standards of ASTM D3363.

The measurement was performed by inserting a measuring pencil and applying a constant load (1Kg). The measurement results are shown as 9H ~ 1H, F, HB, 1B ~ 6B, 9H is the hardest, and 6B shows the weakest hardness.

2. Adhesion to adhesion (Adhension)

It was measured according to the standards of ASTM D3359.

After making a checkerboard-shaped flaw on the coating film using the nano-inorganic composition with a cutter, the 3M tape was completely adhered to the coating film and then peeled off with a certain force to observe the degree of adhesion between the coating layer and the substrate. Measurement results are described as 0B, 1B, 2B, 3B, 4B, 5B, and the numerical values are as follows.

0B: When the coating film is lost more than 65% after measurement.

1B: When the coating film is lost about 35 to 65% after measurement.

2B: When the coating film is lost by 15 to 35% after measurement.

3B: When the coating film is lost by 5 to 15% after measurement.

4B: When the coating film is lost less than 5% after measurement.

5B: When there is no loss of coating film after measurement.

3. Pollution resistant

After applying oily magic to the coating film, it was measured to the extent that the magic was erased after spraying water (tap water), and the results of performing 10 consecutive times at one point were described as follows. ◎: Very good, ○: Good, △: Normal, X: Bad

4. Contact angle

After dropping a drop of water on the coating film, it was observed how the shape of the water on the coating film changed. This is an experiment in which the degree of hydrophilicity of the coating film can be known, and if it is super-hydrophilic or hydrophilic, the cleanability is better. If the contact angle is 20±5 degrees, it can be said to be hydrophilic, and if the contact angle is 10±2 degrees, it can be said to be superhydrophilic.

5. Water resistance

As a result of leaving the base material at a temperature of 90° C. for 12 hours, the state of the coating film was measured.

◎: Very good, ○: Good, △: Normal, X: Bad

6. Transmittance

Using a UV-Visible Spectrometer, the transmittance of the coating film coated on the glass plate was measured from the visible light range to the ultraviolet range.

Claims (19)

The formula _{((x 1 Na 2 O +} x 2 K 2 O + x 3 Li 2 O) · ySiO 2 · nH 2 O) , sodium (Na ₂ O) oxidation alkali metal oxide (M ₂ O) represented by the oxidation At least one of potassium (K ₂ O) and lithium oxide (Li ₂ O) is included; Inorganic acid compounds; And water (H ₂ O);
The number of moles of alkali metal oxides

,

, n is a natural number from 1 to 20,

Satisfies ;,
The number of moles of silica

The nano-inorganic composition satisfying (M ₂ O+ySiO ₂ ) is 0.1 to 10 parts by weight, and a coating film is formed by attaching a nano-inorganic composition containing 0.01 to 2 parts by weight of an inorganic acid compound and the rest of water. Method of forming a nano-inorganic coating.
The method of claim 1,
Method for forming a nano-inorganic coating further comprising the step (S200) of pre-treating (cleaning) the base material.
The method according to claim 1 or 2,
A method of forming a nano-inorganic coating, further comprising a drying step (S300) for removing moisture. The method according to claim 1 to 3,
A method of forming a nano-inorganic coating, further comprising firing (S600) for heat treatment of the coated base material. The method of claim 2,
After the step of pre-treating (cleaning) the base material (S200), the method of forming a nano-inorganic coating further comprises a surface treatment process to facilitate attachment of the composition.
The method of claim 5,
The method of forming a nano-inorganic coating film, characterized in that the surface treatment process uses plasma.
The method of claim 1,
Method for forming a nano-inorganic coating film, characterized in that it further comprises a surfactant in the nano-inorganic composition to facilitate attachment to the base material.
The method of claim 2,
Pre-treatment (washing) of the base material (S200);
Plasma (plasma), anodizing (anodizing), sanding (sanding), etching (etching), alkali cleaning, or a method of forming a nano-inorganic coating comprising pretreatment of acid cleaning.
The method of claim 1,
A method of forming a nano-inorganic coating film, characterized in that the coating film is formed using spray, bar, spin, slot die, vapor deposition, sputtering, dipping, screen printing, sponge, or brush to attach the nano-inorganic composition.
The method of claim 9,
The formation of the inorganic coating film by spraying is a method of forming a nano-inorganic coating film, characterized in that the coating thickness (H _t ) is controlled in proportion to the following equation.

The method of claim 10,
The coating thickness (H _t ) is the flow rate per unit area (Q) is 100 ~ 10,000ul/min, the viscosity (C) is 1 ~ 10cp, the moving speed U of the base material is 0.1 ~ 5m/min, the height of the nozzle is 0.05 ~ 1m. Method for forming a nano-inorganic coating film, characterized in that proportional.
The method of claim 9,
The formation of the inorganic coating film using the bar and the slot die is a method of forming a nano-inorganic coating film, characterized in that the coating thickness (T _wet ) is controlled in proportion to the following equation.

The method of claim 12,
Coating thickness (T _wet ) is proportional to the conditions of bar and slot height 100±50㎛ per unit area, injected flow rate 50~500ul/min, moving speed of base material 1~10 mm/sec. Way. The method of claim 10 or 12,
The coating film thickness (H _t ) is a method of forming a nano-inorganic coating film, characterized in that 10 ~ 5,000nm. The method of claim 9,
A method for forming a nano-inorganic coating film, characterized in that the scattering degree (S) of the inorganic coating film formed by spraying controls haze (turbidity) in proportion to the following equation.

The method of claim 15,
The method of forming a nano-inorganic coating film, characterized in that the haze can be controlled from the first step to the ninth step. The method of claim 15,
Haze is a method of forming a nano-inorganic coating film, characterized in that it can be controlled from the first step to the ninth step according to the surface temperature of the base material. The method of claim 4,
Firing for heat treatment of the coated base material (S600);
A method of forming a nano-inorganic coating further comprising the step of drying at less than 100° C. (S500). The method of claim 4,
Firing for heat treatment (S600); After the cooling step (S700), characterized in that it further comprises a nano-inorganic coating forming method.

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