KR20010100260A - Ceramic coating material using low alkalinity silicate - Google Patents

Abstract

The present invention relates to a ceramic coating material using a low alkali silicate, the object of which is water, weather and corrosion resistance by mixing a low alkaline silicate aqueous solution having a molar ratio (SiO ₂ / M ₂ O) of 3.5 to 5.8 with a curing agent In order to significantly improve the chemical resistance, thermal shock resistance and abrasion resistance, and to cure easily even at low temperatures, it is to maintain a strong adhesive strength.

The present invention the molar ratio of the alkali silicate (SiO ₂ / M ₂ O) is from 3.5 to 5.8 in a low alkali silicate (M ₂ O · nSiO ₂₎ a basic curing agent per 100 parts by weight MgO 20 parts by weight, powdered zinc (Zn) 200 parts by weight Has mixed characteristics

Application of the present invention can significantly improve water resistance, weather resistance, corrosion resistance, chemical resistance, thermal shock resistance, and wear resistance, and can maintain a strong adhesive strength while being easily cured even at low temperatures.

Description

Ceramic coating material using low alkali silicate {CERAMIC COATING MATERIAL USING LOW ALKALINITY SILICATE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic coating material using a low alkali silicate, and in particular, a ceramic polymer in which a metal oxide having high physical properties and excellent protection against thermal shock generated at high temperature and high pressure is dissolved. A coating agent bonded to a silicate.

In recent years, as the high-tech industry develops, various industrial facilities, parts, and tools are used under severe conditions such as high temperature, abrasion, corrosion atmosphere, and the like, and there is a serious problem of shortening their performance and lifespan.

In order to protect industrial equipment, parts or tools used under such severe conditions, a protective coating agent is applied to the outer surface of the surface. For example, a protective coating agent using alkaline silicate, which has been dependent on imports, as an adhesive hardening agent. Has been used.

However, the above-mentioned alkaline silicates mainly have a molar ratio of SiO ₂ / M ₂ O of 2.0 to 3.0, and when an alkaline silicate having such a composition is used as an adhesive curing agent of a protective coating agent, curing progresses slowly, as well as water resistance and thermal shock resistance. There are many limitations and limitations in use because of the lack of cracks in the coating.

The present invention is to solve such a conventional problem, the object is to mix the low alkali silicate having a molar ratio of silicic acid and alkali (SiO ₂ / M ₂ O) 3.5 to 5.8 with a curing agent, water resistance, weather resistance, corrosion resistance, chemical resistance It is to provide a ceramic coating material using a low alkali silicate that can significantly improve the thermal shock resistance, wear resistance, and maintain a strong adhesive strength while being easily cured even at low temperatures.

In order to achieve this object, in a first embodiment of this invention the molar ratio of alkali silicate and that the alkaline silicate (SiO _2/2 M O) is 3.5~5.8 (M _{2 2} O · nSiO) basic with respect to 100 wt. It has the characteristic of mixing with 20 weights of MgOs which are hardening | curing agents, and 200 weights of powdered zinc (Zn), where M is Na, K, Li, and organic amines.

The second embodiment of the present invention the molar ratio of alkali silicate and that the alkaline silicate (SiO ₂ / M ₂ O) is _{3.5~5.8 (M 2 O · nSiO 2} ) a basic curing agent per 100 parts by weight MgO 30 wt nitride, silicate It is characterized by being mixed with 35 weight of Si ₃ N _4, 30 weight of zirconia (ZrO ₂ ), and 5 weight of titanium dioxide (TiO ₂ ) (wherein M is Na, K, Li, and organic amines).

The third embodiment of the present invention the molar ratio of the alkali silicate (SiO ₂ / M ₂ O) is from 3.5 to 5.8 in a low alkali silicate (M ₂ O · nSiO ₂₎ based on 100 parts by weight of aluminum dioxide (Al ₂ O ₃₎ 30 Weight, 40 weight of zirconium byte (SiC), 30 weight of zirconia (ZrO ₂ ), 8 weight of titanium dioxide (TiO ₂ ), 2 weight of antibacterial agent (where M is Na, K, Li, organic amines) .

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described in detail.

The ceramic coating agent of the alkali metal silicate oxide is divided into a bonsai in which the liquid portion, which is an adhesive, and a hardening material and a filler are blended.

As the low alkali silicate used in the present invention, those having a molar ratio (SiO ₂ / M ₂ O) of silicic acid and alkali of up to 3.5 to 5.8 are used.

In addition, the low alkali silicate used in the present invention and Monticellite (MES), which is a solid solution silicide as a metal oxide complex, forms a structure of cubic, in which unit particles are regularly arranged, thereby forming a structure having excellent elasticity and wear resistance. do.

The present invention is composed of a liquid adhesive and a powdery two-component system, which is mixed and applied to a substrate or the like, and can be applied to metals, nonferrous metals, concrete, carbon fiber, glass, porcelain and other combustible materials.

The inorganic oxide coating material obtained in the present invention is characterized by being water-soluble, inorganic, and organic in comparison with general resins, having excellent thermal shock protection and corrosion resistance to various environmental pollutions, as well as high resistance to acid alkali salts. There is no change in the formed film up to ° C, and high heat molding does not change up to 1700 ° C.

The present invention can improve the workability by adjusting the type and content of the curing agent and the inorganic oxide ceramic filler, and by adjusting the molar ratio of the alkali alkali alkali salts, heat-resistant protective agent, a metal coating agent requiring light weather resistance, depending on the use, It can be prescribed for a variety of uses, such as anticorrosive chemical coatings, and building interior and exterior concrete coatings that release antimicrobial far-infrared rays that impart functionality.

Alkali represented by M in this invention is Na, K, Li, organic amines, etc.

As is well known, the silicate alkali has a lower molar ratio of silicic acid and an alkali, that is, a higher alkalinity, is easier to prepare, easier to dissolve, and has a stronger adhesive force, and thus has good storage stability.

Low alkali silicates, on the other hand, are difficult to manufacture, difficult to dissolve, and have poor storage stability.

Low alkali silicate (SiO ₂ / M ₂ O 3.5 to 5.8) applied to the present invention is a kind of high molecular silicate, which has an oligomer (initial to medium high molecular weight) property, and easily cures even at low temperature to form a warning ceramic film. .

In general, when alkali silicate is used as an adhesive for inorganic coating agent, a curing agent may be Zn, ZnO, CaO, MgO, MgCO ₃ , Al (OH) ₃ , AlPO ₄ , weak acid, weak alkali salt of strong acid, or the like.

The structural formula for mixing and curing a low alkaline silicate aqueous solution having a molar ratio of silicic acid and alkali of 3.5 to 5.8 and a curing agent is as follows (when ZnO is used as a curing agent).

MOH (in case M is Na or K), which is liberated in Structural Formula (1), which is an initial curing step, reacts with another Silanol bond (-Si-OH) to form an ionization point of (-Si-O ^- .M ⁺ ), The curing agent again binds to form an insoluble crosslink.

When heated, dehydration condensation proceeds more rapidly at the same time as in Structural Formula (2), and the reaction of Structural Formula (2) proceeds gradually as time passes even at room temperature drying.

The three-dimensional ceramic coating shown in the above structural formula is not only strong itself, but also partially insoluble on the surface, and debonded to the surface of the inorganic sphere, and thus ether bonding by dehydration to the surface of the inorganic sphere 4 ~ 5 compared to the coating film of the organic polymer Reach the ship.

Example 1

In the case of preparing a salt coating for heavy corrosion treatment of iron structures using low alkali silicates having a molar ratio of silicic acid and alkali of 3.5 to 5.8, the composition is as follows.

Low alkali silicate (M ₂ O.nSiO ₂ : molar ratio 4.5, solid content 25)

100 weight

Curing agent (basic) MgO 20 weight

Powdered Zinc Zn 200

Example 2

When a coating agent for high temperature thermal shock protectors is prepared using a low alkali silicate having a molar ratio of silicic acid and alkali of 3.5 to 5.8, the composition is as follows.

Low alkaline silicate (M ₂ O.nSiO ₂ : molar ratio 5.5, solid content 25)

100 weight

Curing agent (basic) MgO 30 weight

Nitride Si ₃ N ₄ 35 Weight

Zirconia ZrO ₂ 30 Weight

Titanium Dioxide TiO ₂ 5 Weight

Example 3

When the low alkali silicate having a molar ratio of silicic acid and alkali of 3.5 to 5.8 is used to prepare concrete deterioration prevention and functional coating, the composition is as follows.

Low alkali silicate (M ₂ O.nSiO ₂ : molar ratio 4.2, solid content 25)

100 weight

Aluminum dioxide Al ₂ O ₃ 30 weight

Zircon Carbide SiC 40 weight

Zirconia ZrO ₂ 30 Weight

Titanium Dioxide TiO ₂ 8 Weight

Antibacterial agent (various metal ions) 2 weight

Hereinafter, test results comparing the characteristics of the ceramic coating material using the low alkali silicate according to the present invention and the coating material widely used in Korea will be described.

The coating material according to the present invention is the present invention material (K-02, K-03, K-04), and CERAMA-BIND (CB) of AREMCO, USA, among the products widely used in Korea, as a comparative material 1, Japan's OTTI Co., Ltd. DARNFORCE CERAMIC (DC) was tested and prepared as Comparative Material 2.

The specimens used in the test were prepared by coating the coating agent on a steel sheet, a glass substrate, an alumina substrate, or by drying the coating material itself.

Test Example 1

Heat resistance test

The present invention, comparative material 1 and comparative material 2 were applied to an alumina substrate, and then heat treated under the conditions of the following Table 1 in an air atmosphere using an electric furnace, followed by cooling to observe the appearance of the specimen.

division K-02 K-03 K-04 Comparative material 1 (CB) Comparative material 2 (DC) Exam conditions 1650 ℃ 8 hours 3 ℃ / min 1250 ℃ 8 hours 3 ℃ / min 850 ℃ 8 hours 3 ℃ / min 1250 ℃ 8 hours 3 ℃ / min 1250 ℃ 8 hours 3 ℃ / min

As a result, in the case of K-02, one of the present invention materials, the chemical reaction between the coating layer and the alumina substrate proceeded, the coating layer penetrated into the substrate, and the color of the olive was changed to pale pink.

K-03 did not change, and in the case of K-04, it was confirmed that the coating layer was raised.

In the case of Comparative Material 1 (CB), it was confirmed that in the case of Comparative Material 2 (DC), the coating layer was severely melted and agglomerated into protrusions.

In addition, as a result of observing the surface of each coating agent with an optical microscope, it was found that in the case of K-02 and Comparative Material 2 (DC) of the present invention, it changed from a porous tissue to a dense structure, and Comparative Material 2 (DC) In the case of cracking was observed.

In the case of K-03 and K-04 of the present invention, when comparing the specimens before and after the heat treatment, it was observed that there was almost no change in the properties, and in the case of Comparative Material 1 (CB), it was severely melted and agglomerated into protrusions. It could be observed.

Test Example 2

Specific gravity and porosity measurement

Specimens prepared using the present invention were impregnated in white kerosene, evacuated under 150 mmHg for 4 hours, and then the volume specific gravity and apparent porosity were measured according to the method of JIS R2205.

The results are shown in Table 2 below.

division K-02 K-03 K-04 Bulk Density (g / cm ³ ) 1.57 1.98 1.59 ApparantPorosity () 41.2 35.3 55.5

Test Example 3

Abrasion Resistance Test

On the 50 × 30 × 40 (t) mm steel plate finely polished on the surface was coated with a coating material of the present invention, Comparative Material 1 (CB) and Comparative Material 2 (DC) and dried to prepare a specimen.

For abrasion resistance test, a Suga Test equipped with # 320 sand paper was used, and a load of 4 kg / m ² was applied as a test condition.

After the wear resistance test under the same conditions as described above, the wear resistance of each specimen was evaluated by measuring the weight change of the specimen.

The results are shown in Table 3 below.

wt 5 times 10th 20 times K-02 -0.007 -0.015 -0.037 K-03 -0.006 -0.014 -0.035 K-04 -0.010 -0.028 -0.055 Comparative Material 1 -0.042 -0.050 -0.066 Comparative Material 2 -0.023 -0.037 -0.069

As a result of the abrasion resistance test, K-02 and K-03 specimens of the present invention showed the best wear resistance, and in the case of K-04, Comparative Material 1 and Comparative Material 2 specimens, the entire coating layer was worn out during 20 tests. .

Table 4 shows the results of measuring the weight loss rate of the coating layer after 20 wear tests of the K-02, K-03, and K-04 specimens of the present invention.

division Specific gravity (g / cm ³ ) Test area on the specimen (cm ² ) Coating layer thickness (cm) Initial weight (g) Abrasion Weight ^* (g) Wear rate () K-02 1.75 3.46 0.0053 0.0321 0.0190 59 K-03 1.98 3.75 0.0026 0.0193 0.0170 88 K-04 1.59 3.64 0.0028 0.0162 0.0260 160

* Abrasion weight was considered to originate only from the coating layer.

Wear rate = wear weight ÷ initial weight × 100 ()

According to Table 4, in the case of K-04, the coating layer was completely removed, and it can be seen that the steel plate was partially worn.

Test Example 4

Chemical resistance test

The coating material of the present invention, Comparative Material 1 (CB) and Comparative Material 2 (DC) was applied over the entire glass substrate of 100 x 40 x 4 (t) mm, followed by 10 aqueous NaCl solution, 10 MgSO ₄ aqueous solution, and HCl 36. The specimen appearance was observed after impregnating the aqueous solution and H ₂ SO ₄ 60 aqueous solution for 10 days.

① HCl solution

As a result of observing the appearance of the specimen after impregnating the coating agent applied to the glass substrate with 36 HCl aqueous solution for 10 days, there was no change in the case of the present invention material K-02, K-03, K-04, the coating layer was No weight loss occurred.

On the other hand, in the case of Comparative Material 1 (CB), there was no discoloration and dropping of the coating layer, but the thickness of the coating layer was thin.

In the case of Comparative Material 2 (DC), the blue reactant was dissolved to make the coating layer thin and the surface rough.

② H ₂ SO ₄ solution

After the coating agent applied to the glass substrate was impregnated in 10H ₂ SO ₄ aqueous solution for 10 days, the specimen appearance was observed.

As a result, in the case of the present invention materials K-02, K-03, K-04 and Comparative Material 1 (CB) there was no dropout or weight loss of the coating layer.

On the other hand, in the case of Comparative Material 2 (DC), the color was slightly changed and white spots were observed, and the surface became rough as the coating component was dissolved.

③ NaCl solution

After coating the coating agent applied to the glass substrate in an aqueous solution of 10NaCl for 7 days, the specimen appearance was observed.

As a result, in the case of the present invention materials K-02, K-03, K-04 and Comparative Material 1 (CB) there was no dropout or weight loss of the coating layer.

On the other hand, in the case of Comparative Material 2 (DC), the color was slightly changed, white spots were observed, and the surface became rough as the coating component was dissolved.

④ MgSO ₄ solution

The coating agent applied to the glass substrate was impregnated in 10 MgSO ₄ aqueous solution for 7 days, and then the specimen appearance was observed.

As a result, in the case of the present invention materials K-02, K-03, K-04, and Comparative Material 1 (CB), there was no dropout or weight loss of the coating layer.

On the other hand, in the case of Comparative Material 2 (DC), the color was slightly changed, white spots were observed, and the surface became rough as the coating component was dissolved.

As a result of the chemical resistance (corrosion resistance) test, in the case of Comparative Material 1 (CB) it can be observed that the edge of the edge drop because the adhesion to the glass substrate is lower than other coating agents.

In the case of Comparative Material 2 (DC), it was observed that the surface of the coating agent became rough due to the dissolution of some coating components by the distilled water itself used in addition to the reaction reagent.

In the case of the present invention materials K-02, K-03, K-04 did not show a special change within the test conditions.

Test Example 5

Bond strength test

Specimens were prepared by coating the coating material of the present invention, comparative material 1 (CB) and comparative material 2 (DC) on a steel plate of 20 × 15 × 2 (t) mm, and used a pull-off test according to ASTM D4541. .

The surface of the coating layer of each specimen was finely ground with sandpaper of # 1000, and then the aluminum stud coated with epoxy resin was closely adhered to the surface of the coating layer coated on the coating specimen, and heat-treated at 150 ° C. for 1 hour. Adhesion was induced.

This test was performed six times for each specimen.

The measured values of adhesion strength for each of the specimens are shown in Table 5 below.

Bond Strength (kg _f / cm ² ) K-02 8.00 ± 2.00 K-03 12.8 ± 3.96 K-04 36.2 ± 4.32 Comparative material 1 (CB) 4.00 ± 1.58 Comparative material 2 (DC) 39.4 ± 7.50

According to the above-described adhesion strength measurement value, K-04 and Comparative material 2 (DC) showed the highest value among the present invention materials, and K-02, K-03 and Comparative material 1 (CB) of the present invention material. It can be seen that the relative value is measured by.

Test Example 6

Hot line expansion rate measurement

Using a coating agent of k-02, k-03, k-04 of the present invention to prepare a 10 × 10 × 50 (L) mm specimens, using a Dilatometer (Theta HD-52) 4 in N ₂ atmosphere It measured up to 1400 degreeC by the temperature increase rate of ° C / mm.

The results are shown in Table 6 below.

Temperature (℃) K-02 K-03 K-04 25 0.01 0.01 0.01 150 0.03 0.02 0.03 300 0.06 0.06 0.05 400 0.10 0.10 0.07 500 0.15 0.14 0.08 600 0.20 0.20 0.09 650 0.24 0.23 0.10 700 0.29 0.25 0.10 750 0.34 0.26 0.07 800 0.39 0.27 0.05 900 0.48 0.33 0.01 950 0.50 0.36 0.00 1000 0.52 0.40 1100 0.56 0.44 1200 0.61 0.49 1300 0.67 0.50 1400 0.73 0.51

According to Table 6 showing the results of the thermal expansion coefficient measurement, the coefficient of thermal expansion of K-02 is the highest among the present invention material, and there was an inflection point estimated to be related to the phase change at around 900 ° C.

In K-03, there was an inflection point near 700 ℃, and above 1200 ℃, the coefficient of thermal expansion did not increase any more and remained constant. In the case of K-03, the coefficient of thermal expansion was the lowest, and it decreased from above 700 ℃ and showed a negative value above 950 ℃.

Test Example 7

Thermal conductivity measurement

15φ × 1 (t) mm sized specimens were prepared using the coating materials of k-02, k-03, and k-04, which are the present invention, and were subjected to laser splash method at room temperature, 500 ° C and 1000 ° C. The thermal diffusivity of each specimen was measured at, and the results are shown in Table 7.

division Room temperature 500 ℃ 1000 ℃ K-02 0.09131 (cm ² / sec) 0.00672 (cm ² / sec) 0.00547 (cm ² / sec) K-03 0.00693 (cm ² / sec) 0.00592 (cm ² / sec) 0.00564 (cm ² / sec) K-04 0.01436 (cm ² / sec) 0.01213 (cm ² / sec) 0.00964 (cm ² / sec)

According to Table 7 showing the temperature conductivity of each specimen, it can be seen that in the present invention, K-03 and K-04, the temperature conductivity increases with increasing temperature, and in the case of K-02, it decreases and then increases again. It can be seen that the tendency to.

Test Example 8

Thermal shock resistance test

The specimens were prepared using the present invention and the coating materials of Comparative Material 1 (CB) and Comparative Material 2 (DC), and were rotated at a speed of 10 rpm using a gas burner while being mounted on a separate rotating body. The test was rapidly repeated 100 times after rapid heating to ℃, and after the completion of the test, peeling of the coating agent and peeling of blister were observed in each specimen.

As a result, the surface state of specimens of K-04 and Comparative material 2 (DC) was the best among the present invention materials, and in the case of K-02, K-03 and Comparative material 1 (CB), the coating layer was released. .

Test Example 9

Microstructure Analysis

The coating material of the present invention, Comparative Material 1 (CB) and Comparative Material 2 (DC) was applied to the steel sheet, and then observed on the cut surface of the coating material by SEM to examine the microstructure, coating thickness, smoothness and surface of the coating material. The adhesion state and the like were evaluated.

As a result, the average coating film thickness of each coating agent apply | coated to the steel plate was K-02: 53micrometer, K-03: 26micrometer, K-04: 28micrometer which are this invention materials, Comparative material 1 (CB): 38micrometer, comparison Ash 2 (DC) was observed at 41 μm.

In addition, the composition of the present invention applied to the steel sheet was observed as shown in Table 8.

wt O Al Si K Cr Cl Fe Zn K-02 8.5 12.4 76.4 2.7 - - - - K-03 24.2 8.0 52.7 7.1 - 8.0 - - K-04 5.3 3.2 57.8 4.3 7.1 - 7.3 15.0

According to Table 8, in the case of the present invention materials K-02, K-03, K-04, Si is the primary phase, and K ₂ O, SiO ₂ , Al ₂ O ₃ , and the like are present in a small amount. In the case of K-04, Zn powder was also present.

In Comparative Material 1 (CB), Al ₂ O ₃ was the main phase, and TiO ₂ , SiO ₂ , Al ₂ O ₃ , Co, Fe ₂ O ₃ , and the like were present in a small amount.

In Comparative Material 2 (DC), Al ₂ O ₃ -SiO ₂ was the main phase, and SiO ₂ , Al ₂ O _3, and the like were present in a small amount.

Test Example 10

Impact test

Prepare a specimen coated with the coating material of the present invention, comparative material 1 (CB), comparative material 2 (DC) on a steel sheet, and through a separate device 290g steel ball and 45g aluminum at a height of 20cm After the ball was freely dropped on the surface of each specimen, the damage surface of the coating agent on the specimen was observed under an optical microscope to compare the occurrence of cracks and the damage area.

The results showed a similar tendency to the wear resistance test results, and the impact resistance was lower in the order of K-02, K-03, K-04, Comparative Material 1 (CB), and Comparative Material 2 (DC).

Table 9 summarizes the results of analyzing the quality characteristics of the present invention, Comparative Material 1 (CB) and Comparative Material 2 (DC) as described above.

Invention material Comparative Material 1 (CERAMA-BIND: CB) Comparative material 2 (DARNFORCE-CERAMIC: DC) Coating substrate test conditions K-02 K-03 K-04 Heat resistance test Melt 1650 ℃ No change 1250 ℃ Partial ridge 850 ℃ Melting 1250 ℃ Melting and flocculation 1250 ℃ Al ₂ O ₃ Substrate Test Temperature Chemical resistance test NaCl, MgSO ₄ aqueous solution No abnormalities such as blister, rust discoloration and peeling. clear Surface Roughness White Spots Glass substrate impregnated for 7-10 days HCl, H ₂ SO ₄ aqueous solution Thickness reduction, no abnormality Rust, Surface Roughness, White Spots Thermal shock resistance test Peeling Peeling No peeling, no blister Peeling No peeling, no blister Steel plate 1000 ℃ 100 times Volume specific gravity (g / cm ³ ) 1.75 1.98 1.59 - - Room temperature measurement Apparent porosity () 41.2 35.3 55.5 - - Temperature conductivity cm ² / sec 500 ℃ 0.0069 0.0059 0.0056 - - LaserSplash Method 1000 ℃ 0.0144 0.0121 0.0096 - - Thermal expansion coefficient × 10 ^-6 / ℃ 500 ℃ 3.00 2.80 1.60 - - ThetaHD-52 1000 ℃ 5.33 3.67 0.11 - - Bond Strength (kg _f / cm ² ) 8.0 12.8 36.2 4.0 39.4 ASTMD4541 Mechanical shock resistance ● ◎ ○ ▲ △ Abrasion Resistance Weight Reduction wt (0.037) (0.035) △ (0.055) △ (0.069) △ (0.065) Suga Test # 320,20

Note 1) Comparison of characteristics: good ●〉 ◎〉 ○〉 ▲〉 △ bad

Note 2) Specific gravity and porosity measurements are made by molding and drying the coating slurry.

Using.

Note 3) Heat resistance and impact resistance vary depending on the substrate for coating and heat treatment conditions

Is expected.

Note 4) The bond strength was averaged after 6 tests.

Note 5) The measured values are not absolute values of each coating product quality and under the same conditions

As a result of precise test, it is valid as data for relative comparison by coatings.

Applying the present invention, such as water resistance, weather resistance, corrosion resistance, chemical resistance, thermal shock resistance, wear resistance can be significantly improved, it is possible to maintain a strong adhesive strength while being easily cured even at low temperatures.

Claims (3)

The molar ratio of alkali silicate and that the alkaline silicate (SiO ₂ / M ₂ O) is _{3.5~5.8 (M 2 O · nSiO 2} ) with respect to 100 parts by weight of a mixture of 20 parts by weight MgO, powder zinc (Zn) 200 parts by weight basic curing agent Ceramic coating material using a low alkali silicate, wherein M is Na, K, Li, organic amines. The molar ratio of alkali silicate and that the alkaline silicate (SiO ₂ / M ₂ O) is _{3.5~5.8 (M 2 O · nSiO 2} ) a basic curing agent per 100 parts by weight MgO 30 wt nitride, silicate of Si ₃ N ₄ 35 parts by weight, Zirconia (ZrO ₂ ) 30 weight, titanium dioxide (TiO ₂ ) ceramic coating using a low alkali silicate, characterized in that mixed with 5 weight (wherein M is Na, K, Li, organic amines). The molar ratio of the alkali silicate (SiO ₂ / M ₂ O) is from 3.5 to 5.8 in a low alkali silicate (M ₂ O · nSiO ₂₎ based on 100 parts by weight of aluminum dioxide (Al ₂ O ₃₎ 30 parts by weight, zirconium carbide (SiC) 40 Ceramic coating agent using a low alkali silicate, characterized in that mixed by weight, 30 weight of zirconia (ZrO ₂ ), 8 weight of titanium dioxide (TiO ₂ ), 2 weight of antibacterial agent (where M is Na, K, Li, organic amines) ).