KR101841968B1 - Method for producing ceramic composition for coating, ceramic composition by the method and coating mehtod using by it - Google Patents

Abstract

The present invention relates to a method for producing a ceramic coating composition, a coating composition thereof, and a coating method using the same. More particularly, the present invention relates to a ceramic coating composition comprising 10 to 50% by weight of barley stone, 10 to 50% by weight of feldspar, , 1 to 20% by weight of soda ash, 1 to 20% by weight of soda ash, 5 to 30% by weight of borax, 1 to 7% by weight of nickel (Ni) and 1 to 10% by weight of wollastonite Melting the mixed mixture to obtain an amorphous sintered body; cooling the amorphous sintered body; pulverizing the cooled cooling body; and grinding the pulverized material to a surface of the metal base material A step of firing the metal base material coated with the composition at a temperature of 700 to 850 캜 for 1 to 20 minutes, and a step of cooling the heat-treated base metal material.
According to the present invention, there is an advantage that a ceramic thin film having particularly excellent corrosion resistance can be formed on the surface of a metal base material without using an organic binder or a high-temperature sintering process. Further, there is an advantage that a ceramic thin film excellent in self-cleaning ability can be formed by radiating far-infrared rays.

Description

FIELD OF THE INVENTION The present invention relates to a method for producing a ceramic coating composition, a coating composition for the same, and a coating method using the coating composition. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a method for producing a ceramic coating composition, a coating composition thereof, and a coating method using the same, and more particularly, to a ceramic coating composition having excellent corrosion resistance without requiring high-temperature sintering, To a method of coating a base material.

BACKGROUND ART In general, various kinds of coating agents for coating surfaces are used for various industrial products in order to improve the protection and functionality of products.

The most popular coating method is coating of organic material, but it has low heat resistance, time after formation of coating film, deterioration, decolorization and peeling due to sunlight and daylight. , Continuous maintenance and management were required to protect the base material.

In order to cope with such a problem, ceramic coating agents have recently been attracting attention from the viewpoints of high heat resistance, aesthetic appearance and human-friendly properties.

Ceramic coating agents that have been used so far include organic ceramic coating agents using organic binders such as silane, acryl silicate, and silicone fluorine polymer compounds and inorganic ceramic coating agents using only inorganic ceramics without using organic binders.

However, the organic ceramic coating agent is easy to apply, but a large amount of various volatile organic compounds (VOCs) are generated due to the used organic binders, thereby causing adverse effects on the environment.

The inorganic ceramic coating agent does not cause environmental pollution. However, in order to fix the inorganic ceramic coating layer to the base material, the inorganic ceramic coating agent must be sintered for a long time through a sintering furnace maintained at 1,100 to 1,700 ° C. There is a disadvantage in that a great heat treatment cost is incurred due to high-temperature sintering.

In order to overcome such disadvantages, Korean Patent No. 10-1703345 discloses a ceramic coating composition obtained by melting a ceramic composition composed of silica, feldspar, sodium, boron, cryolite, titanium dioxide, aluminum oxide, manganese, nickel, , Which is then coated on the base material and then baked at a temperature of 600 to 1000 ° C to form a film.

Although the above-mentioned prior-art patents reduce the cost of expensive heat treatment by heat treatment at a relatively low temperature, there is a limitation in corrosion resistance.

KR 10-1493951 B1 KR 10-1703345 B1

Accordingly, an object of the present invention is to prepare an amorphous ceramic coating composition which has excellent corrosion resistance and does not require high temperature sintering.

In addition, by coating the surface of a metal base material using such a ceramic coating composition, a metal base material having a ceramic coating layer excellent in corrosion resistance is produced.

In order to accomplish the above object, the present invention provides a method for preparing a ceramic coating composition, which comprises 10 to 50 wt% of barley stone, 10 to 50 wt% of feldspar, 1 to 20 wt% of niter, Mixing 1 to 20% by weight of soda ash, 5 to 30% by weight of borax, 1 to 7% by weight of nickel (Ni) and 1 to 10% by weight of wollastonite, Melting the amorphous sintered body to produce an amorphous sintered body; cooling the produced amorphous sintered body; and pulverizing the cooled cooling body.

The melting treatment is performed at 1,000 to 1,400 ° C for 1 to 10 hours.

The ceramic coating composition according to the present invention is characterized in that it is produced through the above-described method.

The coating method according to the present invention includes the steps of: applying the ceramic coating composition to a surface of a metal base material; firing the metal base material coated with the composition at a temperature of 700 to 850 ° C for 1 to 20 minutes; And cooling the heat-treated metal base material.

The step of applying the coating composition to the surface of the metal base material may include coating the coating composition to a thickness of 10 to 2,000 mu m and then applying the coating composition to the base metal material, Drying at a temperature of < RTI ID = 0.0 > 200 C, < / RTI >

The metal base material is a pipe, and the step of performing the sintering treatment is characterized in that the sintering treatment is performed by heating with a high frequency induction heating apparatus.

The heat-treating step is characterized by baking in a box furnace.

According to the present invention, there is an advantage that a ceramic thin film having particularly excellent corrosion resistance can be formed on the surface of a metal base material without using an organic binder or a high-temperature sintering process. Further, there is an advantage that a ceramic thin film having excellent self-cleaning ability can be formed by radiating far-infrared rays.

In addition, it is advantageous in that the manufacturing cost is remarkably reduced because the work is simple and the production efficiency is excellent.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a process flow diagram for manufacturing a ceramic coating composition according to the present invention; FIG.
2 is a process diagram of a ceramic coating method according to the present invention.

Hereinafter, the present invention will be described in detail.

First, a method of manufacturing a ceramic coating composition according to the present invention will be described.

Conventional ceramic coating compositions require the use of organic binders or high temperature sintering in the coating process. In addition, conventionally, a composition having a low-temperature sintering process at 1100 DEG C or less has a limitation in corrosion resistance.

The ceramic coating composition according to the present invention is characterized by being capable of low-temperature sintering and remarkably excellent in corrosion resistance, in order to overcome such disadvantages.

The method for preparing the ceramic coating composition of the present invention comprises 10 to 50% by weight of barley stone, 10 to 50% by weight of feldspar, 1 to 20% by weight of niter, soda ash 1 By weight of borax, 1 to 7% by weight of nickel (Ni), and 1 to 10% by weight of wollastonite; and mixing the mixed mixture with the amorphous sintered body A step of cooling the amorphous sintered body thus produced, and a step of pulverizing the cooled cooling body.

Hereinafter, a method for producing the antibacterial ceramic coating composition according to the present invention will be described in detail with reference to FIG.

Barley stone 10 ~ 50 wt% , feldspar (feldspar) 50 wt% , Niter 1 ~ 20 wt% , Soda ash 1 ~ 20 wt% , borax (borax) 30 wt% 1 to 7% by weight of nickel (Ni), and 1 to 10% by weight of wollastonite.

First, the elvan, feldspar, foundation stone, soda ash, borax, nickel and wollastonite are mixed. At this time, the above-mentioned components are used for the purpose of significantly increasing the corrosion resistance of the ceramic thin film through these components and imparting the functionality of far-infrared radiation. In addition, the thermal expansion coefficient of the composition is similar to that of a metal, especially iron or stainless steel, so that the coating layer, that is, the ceramic thin film has excellent physical properties, but does not cause peeling and has excellent adhesion.

More specifically, the elvan forms a large amount of far-infrared rays to impart deodorizing and antibacterial effects. The feldspar improves the physical properties of the coating layer and also contributes to the improvement of corrosion resistance. The core stone can improve the physical properties of the coating layer, And the like. The soda ash improves the strength of the coating layer and helps the coating layer to be uniformly formed. The borax improves the adhesion of the coating layer, improves the compositional integrity, and improves the strength of the wollastonite Serves to significantly increase the corrosion resistance and strength of the coating layer.

The mixture ratio is 10 to 50% by weight of elvan, 10 to 50% by weight of feldspar, 1 to 20% by weight of corundum, 1 to 20% by weight of soda ash, 5 to 30% by weight of borax, 1 to 7% by weight of nickel, 10% by weight of the ceramic coating composition is mixed. This is because considering the far-infrared ray emissivity, the melting temperature, the corrosion resistance and the adhesion with the base material of the ceramic coating composition to be produced, .

On the other hand, it is obvious that it is possible to further mix known pigments and the like to impart different colors to the coating composition, and the practice thereof is not limited. In addition to pigments, it is of course also possible to further include known components in the field to which this technique belongs in order to improve physical properties.

The particle size of each material used in the mixture is not limited.

And melting the mixed mixture to produce an amorphous sintered body.

Next, the mixed mixture is melt-treated to produce an amorphous sintered body. In this case, the melting treatment means sintering at a temperature of 1,000 to 1,400 ° C. for 1 to 10 hours. When the melting temperature is low, sintering is difficult. When the melting temperature is higher than 1400 ° C., .

In the present invention, since the amorphous ceramic coating composition is produced by sintering the mixture, a ceramic coating having excellent strength, abrasion resistance, adhesion, surface hardness and corrosion resistance is formed without performing a high temperature sintering process at 1,100 ° C or more Can be.

Cooling the produced amorphous sintered body.

Then, the produced amorphous sintered body is cooled. The cooling may be performed by a dry method such as leaving at room temperature, using cold air or passing through a cooling roller, or employing a wet cooling method in which water is added to cool the material. Do not.

Since the method of cooling the sintered body is well known in the field of the technology, detailed description thereof will be omitted. The sintered body may be cooled to such an extent that the sintered body can be pulverized. The sintered body is usually about 20 to 50 캜, but is not limited thereto.

The heating rate and cooling rate at the time of the melting treatment and cooling are not particularly limited and the temperature can be raised or cooled while the temperature or the cooling rate is kept constant and the temperature can be increased or decreased while varying gradually or discontinuously There is no restriction on the implementation.

The cooled Cooling water  Crushing step.

And the cooled cooling product is pulverized. The pulverization can also be carried out by dry milling and used as a powder coating composition. Alternatively, the cooling product may be pulverized, that is, wet milled with water to be used as a liquid coating composition, or may be wet pulverized and then cooled again, And may be used as a coating composition in a powder form.

Also, the grain size is not limited to a large extent, but may be about 1 to 300 mu m.

As described above, the antimicrobial ceramic coating composition according to the present invention is characterized in that it has a high emissivity of far-infrared rays, an excellent adhesion to a base material, and particularly excellent corrosion resistance. In addition, since it is an amorphous structure, it is characterized in that these characteristics are exhibited even when a high temperature sintering process is not included in coating.

Hereinafter, a method of coating a metal base material using the coating composition of the present invention will be described in detail with reference to FIG.

The coating method according to the present invention includes the steps of applying the composition to the surface of a metal base material, firing the metal base material coated with the composition at a temperature of 700 to 850 캜 for 1 to 20 minutes, And cooling the metal base material.

The ceramic coating composition described above was mixed with a metal Of base metal  Applying to the surface.

First, the above-mentioned ceramic coating composition is applied to the surface of the metal base material. As described above, the ceramic coating composition may be in a powder state or in a liquid state, and the kind thereof is irrelevant.

As the base material, various kinds of metal materials can be used, but in particular, a base material of a material including iron or stainless steel can be used. This is because the high-frequency induction heating apparatus or the box furnace is used in the heat treatment step to be described later, so that it is easier to heat when a material including iron or stainless steel is used.

In addition, the present invention can be applied to various types of metal base materials. In particular, the present invention is characterized in that pipes which are difficult to apply the conventional ceramic coating can also be used. In other words, a pipe requiring high corrosion resistance and high acid resistance is required to use a thick stainless steel material as it is in a circular shape. However, most of the pipes are unlikely to be used due to high cost of materials, and corrosion resistance and acid resistance are remarkably deteriorated when iron materials are used. According to the present invention, it is possible to produce a low-cost ceramic pipe because it can secure high corrosion resistance and acid resistance by coating the composition of the present invention while reducing the thickness of stainless steel as well as iron. It goes without saying that various types of metal base materials other than pipes can be used.

If the thickness of the coating layer is less than 10 mu m, it is difficult to secure sufficient physical properties. If the thickness of the coating layer is more than 2,000 mu m, This is because the cost increases without increasing the physical properties of the product, which is not efficient. The thickness of the coating layer can be controlled according to the number of coatings, the coating method, and the like.

As the coating method, various methods known in the art can be applied. Examples of the coating method include a dip coating method, a powder coating method, a spray coating method, a brushing method, a spray coating method (thermal spraying) may be used. That is, it can be appropriately selected according to the type and the shape of the base material and the thickness of the required coating layer, and the spray coating or the thermal spraying is most preferably used.

When the coating composition is applied to the metal base material To  Drying step.

Next, the metal base material to which the coating composition is applied is dried. The drying may be performed in a drying chamber at a temperature of 30 to 200 DEG C, and the drying time is not limited. That is, the drying is performed until the coating layer is sufficiently dried, and the drying time varies depending on the drying temperature, but is usually about 5 minutes to 1 hour.

However, when the ceramic composition is applied using the powdery coating composition, the drying step may be omitted.

The dried metal Base material  And calcining at a temperature of 700 to 850 캜 for 1 to 20 minutes.

The dried metal base material is fired at a temperature of 700 to 850 DEG C for 1 to 20 minutes.

At this time, a high-frequency induction heating apparatus or a box furnace is used as the heat treatment.

Here, the high-frequency induction heating apparatus refers to a device that places a conductor serving as an object to be heated in a coil and causes an eddy current to be generated near the surface of the metal conductor when a high-frequency current is passed therethrough, And the dried metal base material is subjected to firing treatment as an object to be heated. Such a high frequency induction heating apparatus is useful when the metal base material is a pipe.

In addition, the box furnace uses a heat source of electric or gas, a box type stationary furnace in which a large quantity is charged at one time and a furnace, and a tunnel type continuous furnace rotatably mounted in a jig. The size of the box is made proportional to the size of the base material, and a jig and a cart are used. At this time, the bogie can be used automatically by attaching a motor. In addition, depending on the shape of the base material, rails may be provided on the lower part of the continuous firing furnace and laid on the jig, or rails may be installed on the upper part of the firing furnace,

In addition, although the baking treatment temperature is conventionally higher than 1,100 ° C in the present invention, the ceramic coating film is sufficiently formed by heat treatment at a temperature of 700 to 850 ° C, and its physical properties are also remarkably improved. At this time, the calcination treatment time may be 1 to 20 minutes.

remind Heat-treated  Metal base material To  Cooling step.

Next, the heat-treated metal base material is cooled to about room temperature through a known method to complete the coating operation.

The surface of the coated metal base material is smooth and glossy, and the adhesion between the coating layer and the metal base material is excellent. In addition, it is particularly excellent in acid resistance, strength, heat resistance and abrasion resistance.

Accordingly, there is provided a ceramic-coated metal base material which does not contain an organic binder, does not require high-temperature sintering and does not cause environmental pollution in a simple manner, and has characteristics of high quality, i.e., high acid resistance, high strength, high heat resistance and high abrasion resistance There are advantages to be able to.

On the other hand, if necessary, prior to application of the coating composition of the present invention, a pretreatment may further include steps such as sandblasting and surface polishing so as to remove foreign substances or grease from the surface of the metal base material and improve the adsorption force of the coating composition , Its implementation is not limited.

However, as described above, since the surface of the coated metal base material according to the present invention is smooth and glossy, a post-finishing operation such as a separate grinding or polishing process is unnecessary.

Further, since the present invention is excellent in adhesion and does not cause peeling of the coating layer, an acid treatment step of forming fine unevenness on the surface of the metal base material as a pretreatment is not required.

Hereinafter, the present invention will be described in more detail with reference to specific examples.

(Example 1)

A coating material was prepared which contained 30% by weight of elvan, 25% by weight of feldspar, 10% by weight of cornerstone, 10% by weight of soda ash, 15% by weight of borax, 5% by weight of nickel and 5% by weight of wollastonite. Then, the amorphous sintered body was melted at 1200 ° C. for 3 hours, cooled to room temperature, and then milled to a size of 1 to 300 μm.

The dry milled composition was powder coated onto the surface of the base material. The mixture was calcined in a box furnace at 800 ° C for 10 minutes, and then cooled at room temperature. The thickness of the coated film was 100 mu m.

Here, as the base material, a stainless steel 304 steel plate having a thickness of 2T and a reinforcing bar D22 specified in KS D 3504 were used.

(Comparative Example 1)

The coating material was prepared in the same manner as in Example 1 except that 25 wt% of silica, 20 wt% of feldspar, 10 wt% of sodium, 6 wt% of boron, 6 wt% of cryolite, 6 wt% of titanium dioxide, 6 wt% of manganese, and 5 wt% of nickel were mixed and used.

(Test Example 1)

The far infrared ray emissivity of Example 1 was tested. The test method was followed in accordance with KCL-FIR-1005; 2011 and measured by FT-IR spectrometer. As the test piece, a stainless steel 304 plate (10 cm x 10 cm, 2T) having the coating layer of Example 1 was used.

Results of Test Example 1 Test Items unit Test result Remarks Far-infrared emissivity
(Measurement temperature: 40 占 폚, measurement wavelength: 5 占 퐉 to 20 占 퐉) - 0.855 (22.4 ± 0.1) ° C
(24.2 ± 0.3)% RH
Far-infrared radiation energy
(Measurement temperature: 40 占 폚, measurement wavelength: 5 占 퐉 to 20 占 퐉) W / ㎡ 3.12 x 10 ² (22.4 ± 0.1) ° C
(24.2 ± 0.3)% RH

As can be seen from the above Table 1, Example 1 shows that the far infrared ray emissivity reaches 85% and has a high radiant energy.

(Test Example 2)

The acid resistance of Example 1 and Comparative Example 1 was tested using 68% nitric acid (HNO ₃ ), 98% sulfuric acid (H ₂ SO ₄ ), 35% hydrochloric acid (HCl) and 55% hydrofluoric acid (HF). For the acid resistance test, specimens were prepared so that the reinforcing bars formed with the coating layers of Example 1 and Comparative Example 1 had a length of 3 cm.

Test methods were as follows: Acet (one each of nitric acid, sulfuric acid, hydrochloric acid, and hydrofluoric acid) and B set (nitric acid, sulfuric acid, hydrochloric acid, and hydrochloric acid) containing two 150 ml of nitric acid, 150 ml of sulfuric acid, And one set of each one of the hydrofluoric acid). Thereafter, the specimen of Example 1 was placed in a paper cup of Aset and the specimen of Comparative Example 1 was placed in a paper cup of B set. After 24 hours, the specimen was taken out and the degree of redness A digital area meter was used to measure the corrosion area rate. At this time, the calculation of the corrosion area ratio was made as corrosion area / measurement area × 100. The temperature of each acid was maintained at 20 ° C.

As a control, reinforcing bars having no coating layer were prepared in the same size.

Test Example 2 Results division nitric acid Sulfuric acid Hydrochloric acid Foshan Example 1 0 0 0 0 Comparative Example 1 2 0 0 21 Control group 94 92 93 98

As can be seen from the above Table 2, it was confirmed that in Example 1, no reaction was observed in all of nitric acid, sulfuric acid, hydrochloric acid and hydrofluoric acid. On the other hand, in Comparative Example 1, it was confirmed that there was no reaction with sulfuric acid and hydrochloric acid. However, slight corrosion occurred in nitric acid and hydrofluoric acid, and a large amount of corrosion was observed in nitric acid, sulfuric acid, hydrochloric acid and hydrofluoric acid.

(Test Example 3)

The salt test of Example 1 and Comparative Example 1 was conducted. For the salt water test, specimens were prepared so that the reinforcing bars formed with the coating layers of Example 1 and Comparative Example 1 had a length of 3 cm. The salt water test was conducted by immersing the specimen of Example 1 and Comparative Example 1 in a 7% aqueous solution of sodium chloride and an aqueous solution of 15% of sodium chloride for 30 days (at a temperature of 30 캜 of sodium chloride aqueous solution) And the corrosion area ratio was calculated. At this time, the calculation of the corrosion area ratio was made as corrosion area / measurement area × 100.

As a control, reinforcing bars having no coating layer were prepared in the same size.

Test Example 3 Results division 7% 15% Example 1 0 0 Comparative Example 1 0 2 Control group 96 98

As can be seen from the above Table 3, in Example 1, it was confirmed that no corrosion was observed as a result of the salt water test.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments. It will also be appreciated that many modifications and variations will be apparent to those skilled in the art without departing from the scope of the invention.

Claims (7)

delete 10 to 50% by weight of barley stone, 10 to 50% by weight of feldspar, 1 to 20% by weight of niter, 1 to 20% by weight of soda ash, 5 to 30% by weight of borax 1 to 7% by weight of nickel (Ni) and 1 to 10% by weight of wollastonite,
Melting the mixed mixture at 1,000 to 1,400 ° C for 1 to 10 hours to produce an amorphous sintered body;
Cooling the produced amorphous sintered body,
And milling the cooled cooling product. ≪ RTI ID = 0.0 > 11. < / RTI >
A ceramic coating composition produced by the process of claim 2.
Applying the ceramic coating composition of claim 3 to the surface of the metal base material,
Firing the metal base material coated with the composition at a temperature of 700 to 850 캜 for 1 to 20 minutes;
And cooling the heat treated metal matrix. ≪ RTI ID = 0.0 > 11. < / RTI >
5. The method of claim 4,
Wherein the step of applying the coating composition to the surface of the metal base material comprises applying the coating composition to a thickness of 10 to 2,000 mu m,
After the step of applying the coating composition to the metal base material,
Further comprising a step of drying the metal base material coated with the coating composition at a temperature of 30 to 200 캜, followed by baking treatment.
6. The method of claim 5,
The metal base material is a pipe,
The step of heat-
And heating by a high-frequency induction heating apparatus to heat-treat the ceramic coating composition.
The method according to claim 6,
The step of heat-
Lt; RTI ID = 0.0 > (Box). ≪ / RTI >

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