KR20110109195A

KR20110109195A - Ceramic coating composition with high heat resistance

Info

Publication number: KR20110109195A
Application number: KR1020100028802A
Authority: KR
Inventors: 김선권
Original assignee: 김선권
Priority date: 2010-03-30
Filing date: 2010-03-30
Publication date: 2011-10-06

Abstract

The present invention relates to a heat-resistant ceramic coating composition, and in particular, an environmentally friendly heat-resistant ceramic coating composition that can prevent cracking and peeling of the coating film due to elasticity at high temperature while preventing generation of harmful substances. It is about. The heat resistant ceramic coating composition is prepared by adding a filler to a binder prepared by mixing a dispersion solution of a silica sol and a metal hydroxide solution containing 20 to 50 wt% of a solid component dispersed in water.

Description

Ceramic Coating Composition with High Heat Resistance

The present invention relates to a heat-resistant ceramic coating composition, and in particular, an environmentally friendly heat-resistant ceramic coating composition that can prevent cracking and peeling of the coating film due to elasticity at high temperature while preventing generation of harmful substances. It is about.

The heat resistant paint refers to a paint that breaks down the coating film such as discoloration, cracking, softening or peeling, even when applied to an object that maintains a high temperature of 100 ° C. or higher. Aluminum, zinc, graphite, tin, cadmium powder or quartz may be used as the pigment for the heat resistant paint, and silicone resin may be used as the binder. Silicone resin paints known as heat resistant paints are known to withstand several hours at about 500 ° C.

Heat-resistant paints can be used in desulfurization plants, power plants, dust collectors, incinerators, incineration boilers, or crematoriums, as well as in interior or exterior coatings of general buildings as needed. Heat-resistant paints used for a variety of applications not only have to have heat resistance suitable for the purpose, but also need to have a property that can correspond to the elongation of the coating material according to the temperature. On the other hand, it is necessary to prevent the contaminants from penetrating into the interior and not generate harmful substances at high temperatures.

Known heat-resistant paints can be applied only to temperatures below 400 ° C and are difficult to respond to changes in the surface of the coatings with temperature, and can cause harmful substances at high temperatures due to the addition of organic or metal compounds added to improve heat resistance. Has the problem that it can.

The present invention has been made to solve the above problems of known heat resistant paints and has the following object.

An object of the present invention is to provide a heat-resistant ceramic coating composition which is excellent in heat resistance without generating any volatile organic matter and at the same time can cope with stretching of a coating material according to temperature.

According to a preferred embodiment of the present invention, a heat resistant ceramic coating composition is prepared by adding a filler to a binder prepared by mixing a dispersion solution of a silica sol and a metal hydroxide solution containing 20 to 50 wt% of a solid component dispersed in water. do.

According to another suitable embodiment of the present invention, the metal hydroxide is at least one selected from the group consisting of lithium hydroxide, aluminum hydroxide, sodium hydroxide and potassium hydroxide.

According to another suitable embodiment of the present invention, the filler is silicon nitride (SiN), minugel, magnesium oxide (Mg ₂ O ₃ ), silicon carbide (SiC), carbon (C), aluminum phosphate, zirconium oxide (ZrO ₂ ) At least one selected from the group consisting of nihad, zinc oxide, and lithium boric acid (LiB).

According to another suitable embodiment of the present invention, the weight ratio of the silica gel sol dispersed in water is silica gel sol: water = 100: 120-40.

According to another suitable embodiment of the present invention, the weight ratio of metal hydroxide to water in the metal hydroxide solution is water: metal hydroxide = 100: 200-20.

According to another suitable embodiment of the present invention, the dispersion solution and the metal hydroxide solution are in a weight ratio of dispersion solution: metal hydroxide solution = 100: 10-50.

According to another suitable embodiment of the present invention, the weight ratio of filler to binder is binder: filler = 100: 10 to 100.

The heat-resistant ceramic coating composition according to the present invention has an advantage that the breakdown of the coating film does not occur for a predetermined time at a high temperature of about 1500 ° C., so that it can be applied to all applications. The composition according to the present invention has an advantage in that peeling or detachment of the coating film due to repetition of high temperature and low temperature can be prevented by having an elongation corresponding to the elongation of the coating material according to the temperature. In addition, the coating composition according to the present invention has an advantage that it does not generate volatile organic compounds or other harmful substances at high temperatures and has environmental friendliness.

1 schematically illustrates a manufacturing process of a heat resistant ceramic coating composition according to the present invention.
2 and 3 show a photograph of the test results of the ceramic coating composition in the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and embodiments. The examples are intended for a clear understanding of the invention and should not be construed as limiting the scope thereof.

1 schematically illustrates a manufacturing process of a heat resistant ceramic coating composition according to the present invention.

Referring to Figure 1, the manufacturing process of the ceramic coating composition is to disperse the silica sol in water to prepare a dispersion solution (S11), to prepare a metal hydroxide solution (S12), by adding a metal hydroxide solution to the dispersion solution Preparing a binder (S13) and adding a filler (14).

Silica sol or colloidal silica refers to a solution whose surface is preserved in a sol state with siloxane groups in the form = Si-O-Si = or silanol groups in the form of? Si-OH. Silica (SiO ₂ ) in the silica sol can exist in the particulate state having a particle average diameter of 1 to 1000 nm and is generally negatively charged. The silica sol may comprise from 20 to 50 wt% of the solid component (silica) and preferably comprises from 30 to 45 wt% of the silica sol comprising any solid component for the preparation of the dispersion solution according to the invention. Silica sol comprising a solid component can be used. The dispersion solution can be made by adding water to the silica sol. Water can be ion exchanged or distilled water and can be added with stirring. The amount of water added may be silica sol: water = 100: 120-40 in weight ratio. When the dispersion solution is made (S11), a metal hydroxide solution for mixing with the dispersion solution may be prepared (S12).

By metal hydroxide solution is meant a mixture of LiOH, KOH, NaOH or Al (OH) ₃ and water, for example. When the metal hydroxide is added to the water, the exothermic reaction proceeds, so the metal hydroxide should be added to the water while maintaining a constant temperature. The temperature may be for example 35 to 70 ° C. and metal oxides may be added to the water at a constant rate with stirring. One or more metal hydroxides may be added to the water. For example, LiOH, NaOH, KOH may be added alone or KOH and Al (OH) ₃ may be added together. The amount of metal hydroxide added to the water may be determined depending on the saturation conditions of the respective metal hydroxides at room temperature, but may be water: metal hydroxide = 100: 200 to 20 by weight. However, extremely low solubility metal hydroxides such as Al (OH) ₃ may be added in small amounts. For example, Al (OH) ₃ may be added in an amount of 0.05 to 1.0 parts by weight based on 100 parts by weight of water, or may be added in an amount that becomes saturated at room temperature.

The prepared metal hydroxide may be added to the dispersion solution to make a binder (S13). When the metal hydroxide is added to the dispersion solution, the exothermic reaction may proceed. Therefore, the metal hydroxide needs to be added at a constant rate while maintaining the dispersion solution at a constant temperature. In the addition process, the temperature is maintained at 30 to 70 ° C. and the amount of the metal hydroxide added may be a dispersion solution: metal hydroxide solution = 100: 10 to 50 in weight ratio. The binder may be applied directly to the workpiece, but may be applied to the workpiece after the addition of a filler to improve the coating properties.

Fillers include silicon nitride (SiN), minugel, magnesium oxide (Mg ₂ O ₃ ), silicon carbide (SiC), carbon (C), aluminum phosphate, zirconium oxide (ZrO ₂ ), nihad, zinc oxide, or boronium (LiB) It may be a compound such as). Minugel refers to a material consisting of SiO ₂ / Al ₂ O ₃ / Fe ₂ O ₃ / TiO ₂ / P ₂ O ₅ / CaO / MgO / K ₂ O / CO ₂ , and Nihad is a CaO / SiO ₂ / Refers to a material consisting of a component of Fe ₂ O ₃ / Al ₂ O ₃ / MnO / TiO ₂ / K ₂ O. The filler may be selected as one or more components and added to the binder and the components added may be appropriately selected depending on the application. The filler may be made into a powder form having an average diameter of 5 nm to 100 μm and added to the binder (S14). The amount added may be binder: filler = 100: 10-100 by weight.

When a properly selected filler is added to the binder, the heat resistant ceramic paint is completed.

Hereinafter, an embodiment of a heat resistant ceramic paint according to the present invention will be described.

Example

Example 1

Step 1: 20 kg of a silica sol having 40 wt% of solid component was dispersed in 14 kg of water with stirring to prepare a dispersion solution.

Step 2: 3.8 kg of potassium hydroxide (KOH) was added to 4 kg of water with stirring while maintaining a temperature of 40-90 ° C. to prepare a metal hydroxide solution. In the course of the addition, the heater was stopped while reaching a temperature of 80 ° C. such that the maximum temperature did not exceed 90 ° C.

Step 3: A binder was prepared by adding a metal hydroxide solution to the dispersion solution with stirring at a constant rate while maintaining the temperature at 40 to 60 ° C.

Step 4: 200 g of silicon nitride (SiN), 200 g of minugel, 200 g of magnesium oxide (Mg ₂ O ₃ ), 300 g of silicon carbide and 20 g of carbon (graphite) were stirred in the powder with stirring It was added to prepare a coating composition.

Example 2

A binder was prepared in the same manner as in Example 1. 60 parts by weight of silicon carbide and 40 parts by weight of silicon nitride were added to 200 parts by weight of the binder to prepare a coating composition.

Example 3

A binder was prepared in the same manner as in Example 1. 100 parts by weight of Minugel, 100 parts by weight of aluminum phosphate, 150 parts by weight of zirconium oxide, 100 parts by weight of nihad and 100 parts by weight of silicon nitride were added to 1000 parts by weight of the binder to prepare a coating composition.

Example 4

A binder was prepared in the same manner as in Example 1. A paint composition was prepared by adding 3.2 parts by weight of aluminum phosphate, 3.2 parts by weight of minugel, 4.8 parts by weight of zinc oxide, and 4.8 parts by weight of Nihad, based on 32 parts by weight of the binder.

Example 5

A binder was prepared in the same manner as in Example 1. A coating composition was prepared by adding 650 parts by weight of silicon carbide (SiC), 150 parts by weight of silicon nitride (SiN), 300 parts by weight of zinc oxide (ZnO), and 60 parts by weight of lithium boric acid (LiB).

Example 6

A binder was prepared in the same manner as in Example 1 except that the solid content of the silica sol was 30 wt%. 320 parts by weight of silicon carbide (SiC), 150 parts by weight of zinc oxide and 100 parts by weight of lithium borosilicate were added to 1000 parts by weight of the binder to prepare a coating composition.

Example 7

Step 1: 20 kg of silica sol having 40 wt% solids was dispersed in 12 kg with stirring to make a dispersion solution.

Step 2: An additive door metal hydroxide solution was prepared, while 1 kg of sodium hydroxide (NaOH) was stirred in 5 kg of water with stirring while maintaining a temperature of 40 to 90 ° C. During the addition process, the maximum temperature was adjusted to not exceed 90 ° C.

Step 4: 200 g of silicon nitride (SiN), 250 g of magnesium oxide (Mg ₂ O ₃ ) and 400 g of silicon carbide were added to the binder with stirring in powder form to prepare a coating composition.

Example 8

A binder was prepared in the same manner as in Example 7. 60 parts by weight of silicon carbide and 40 parts by weight of magnesium oxide were added to 200 parts by weight of the binder to prepare a coating composition.

Example 9

A binder was prepared in the same manner as in Example 7. 100 parts by weight of Minugel, 100 parts by weight of aluminum phosphate, and 150 parts by weight of zirconium oxide were added to 1000 parts by weight of the binder to prepare a coating composition.

Example 10

Step 1: 20 kg of a silica sol having 35 wt% of solid component was dispersed in 10 kg of water with stirring to prepare a dispersion solution.

Step 2: 2 kg of lithium hydroxide (LiOH) was added to 5 kg of water while maintaining a temperature of 40-90 ° C. with stirring to prepare a metal hydroxide solution. During the addition process, the maximum temperature was adjusted to not exceed 90 ° C.

Example 11

A binder was prepared in the same manner as in Example 10. 60 parts by weight of silicon carbide and 40 parts by weight of silicon nitride were added to 200 parts by weight of the binder to prepare a coating composition.

Example 12

A binder was prepared in the same manner as in Example 10. 100 parts by weight of Minugel, 100 parts by weight of aluminum phosphate, 150 parts by weight of zirconium oxide, 100 parts by weight of nihad and 100 parts by weight of silicon nitride were added to 1000 parts by weight of the binder to prepare a coating composition.

Test and results

end. Specimen Preparation

The surface of the SS400 iron specimens was treated in a sand blast manner and the coating composition prepared according to Examples 1-12 was coated with an air gun over two times. The coating film was naturally dried, and then applied twice over and dried naturally. Thereafter, the coated iron specimens were dried at 50 to 60 ° C. for 10 minutes in a drying furnace for 15 minutes at a temperature of 150 to 160 ° C., and then cooled to room temperature.

I. Thermal shock test

Specimens prepared for the thermal shock test were placed in an electric furnace and kept at a temperature of 820 to 1,010 ° C. for 10 minutes. The specimen was again taken out and cooled to room temperature. The state change of the specimen was confirmed and placed in an electric furnace for 20 minutes at a temperature of 1,010 ° C. The specimen was again taken out and cooled to room temperature. After checking the state of the specimen, the specimen was placed in an electric furnace and left for 60 minutes at a temperature of 1,010 ° C. After the specimen was taken out and cooled to room temperature.

All. Peel test

In order to confirm the peeling of the coating object and the coating film, the specimen was maintained in an electric furnace at 450 ° C. for 10 minutes, and then taken out and immersed in water to confirm the surface state of the specimen. The specimen cooled to room temperature was placed in an electric furnace at 700 ° C. for 10 minutes, and then the specimen was taken out and cooled to room temperature. Since the same process was repeated using an electric furnace maintained at a temperature of 800 ℃ and a temperature of 1,000 ℃.

la. result

The test was repeated five times on specimens impregnated with water after holding in an electric furnace at 450 ° C. and peeling was found only at some corners of the specimens. At the same time, microscopic examination of the peeled edges revealed a fine crack.

In the case of the test specimen not impregnated with water as shown in FIG. On the other hand, it was found that the opposite side of the specimen, which is not applied with the coating composition, as shown in FIG. 3A and 3B show the test results at 1000 ° C., and FIG. 3A corresponds to the photographs before and after the test on the front surface of the coating, and FIG.

The coating composition according to the invention has the advantage that it is applied to any workpiece to improve the fire resistance performance. In particular, it has the advantage that it can be applied to the required device of high temperature of 800 ℃ or more, such as incinerator. In addition, the coating composition according to the present invention has an advantage of not only generating volatile organic compounds or harmful components in the manufacturing process or painting process but also generating environmentally friendly components after generating the coating film.

Although the invention has been described in detail above by the implementation shown, the embodiments presented are exemplary and the invention is not limited to the embodiments shown. Those skilled in the art will be able to make various changes and modifications without departing from the spirit of the present invention from the presented embodiments. It is apparent that the present invention is not limited by these variations and modifications.

S11: Dispersion Solution Preparation
S12: preparation of metal hydroxide solution
S13: Binder Manufacturing
S14: Filler added

Claims

A heat resistant ceramic coating composition prepared by adding a filler to a binder prepared by mixing a dispersion solution of a silica sol and a metal hydroxide solution containing 20 to 50 wt% of a solid component dispersed in water.

The heat resistant ceramic coating composition according to claim 1, wherein the metal hydroxide is at least one selected from the group consisting of lithium hydroxide, aluminum hydroxide, sodium hydroxide and potassium hydroxide.

The method of claim 1, wherein the filler is silicon nitride (SiN), minugel, magnesium oxide (Mg ₂ O ₃ ), silicon carbide (SiC), carbon (C), aluminum phosphate, zirconium oxide (ZrO ₂ ), nihad, zinc oxide And at least one selected from the group consisting of boric lithium (LiB) heat-resistant ceramic coating composition.

The heat-resistant ceramic coating composition according to claim 1, wherein the weight ratio of the silica gel sol dispersed in the water is silica gel sol: water = 100: 120-40.

The heat resistant ceramic coating composition according to claim 1, wherein the weight ratio of the metal hydroxide to water in the metal hydroxide solution is water: metal hydroxide = 100: 200 to 20.

The heat-resistant ceramic coating composition according to claim 1, wherein the dispersion solution and the metal hydroxide solution are in a weight ratio of dispersion solution: metal hydroxide solution = 100: 10 to 50.

The heat resistant ceramic coating composition according to claim 1, wherein the weight ratio of the filler to the binder is binder: filler = 100: 10 to 100.