KR100953829B1 - Watersoluble ceramic paint composition having improved cohesion quality at high temperature - Google Patents

Abstract

The invention of the heat shield function, and that the binding force of the ceramic excellent aqueous coating composition, of titanium oxide with heat shield function component, antimony di-chromic acid, and mixtures SiC, SiO ₂ -Al ₂ O ₃ to block heat from the hot electrode inclusion and, when exposed to a high temperature heat source coupled to strengthen the bonding force between the ceramic coating agent _{Al 2 O 3 -MgO-SiO 2} -Na 2 OK 2 O, tungsten carbide, silicate, sodium mixture (Na ₂ · 3SiO ₂ ), And an aqueous ceramic coating composition having excellent heat shielding and bonding strength at an extremely high temperature containing silicon dioxide.

The present invention, when applied to the outer surface of the aircraft or spacecraft, such as a high temperature fire-resistant, friction with the air, such as aircraft, the heat shielding properties at the extremely high temperature that the bonding force is increased in the very high temperature region than in the low temperature region And an aqueous ceramic coating composition having excellent bonding strength.

Paints, ceramic paints, binders, heat shields, Al2O3-MgO-SiO2-Na2O-K2O, tungsten carbide, sodium silicate, silicon dioxide.

Description

Water-soluble ceramic paint composition having improved cohesion quality at high temperature}

The present invention relates to a ceramic-based water-based coating composition having excellent heat shielding ability to block heat at a high temperature, and excellent bonding force of the coating film, so that there is no buckling or hole generation of the heat shielding coating film at a high temperature.

In recent years, the laboratory has been working at high temperatures, industrial furnaces used in the steel industry, electric furnaces, kilns used in the cement industry, and fire furnaces used in ceramics, such as the ceramics industry, and high-speed friction with air. Research on heat shielding paints with thermal barrier compositions such as exterior walls of aircrafts or spacecrafts that are generated is being actively conducted. In addition, heat shielding paint compositions for reducing cooling or heating costs such as buildings, liquid storage tanks, buildings of distribution centers, large buildings, museums, high-rise buildings, indoor swimming pools, etc. are being actively studied at low and medium temperatures. However, very little research has been conducted on water-based ceramic coating compositions having excellent heat shielding properties and bonding strength at high temperatures other than the low and mid-temperature ranges. Moreover, there is little research on ceramic coatings that have always maintained the bonding force between ceramic components at high temperatures. Seems.

Medium and low temperature heat-resistant coating composition is mainly a composition containing an organic polymer resin is used to reduce the energy cost according to the season and maintain a constant internal temperature, heat-shielding paint at high temperature is energy The main purpose is to protect the object from ignition, destruction and explosion due to high temperature, rather than saving. For example, it may be the same as the case where micro holes are generated due to the departure of the insulation board of the space shuttle, and high temperatures are concentrated in the micro holes, leading to the explosion of the spacecraft. In the case of an object exposed to a very high heat source, the internal temperature rises rapidly, thereby preventing the temperature rise inside the object by blocking a phenomenon in which the external heat is transferred to the interior, thereby preventing the safety accident or explosion or fire as much as possible. It can be seen as a purpose. In addition, unlike heat shield paints at high temperatures of 1000 ° C. or higher, organic polymer materials that ignite or decompose at high temperatures cannot be used at all. Therefore, high temperature heat shield paints are made of inorganic ceramic materials. It can be said that it is made only of water-based paints. In this case, the main problem is that the bonding strength is generally weak because hydrogen bonding, metal bonding, ionic bonding, adsorption or anchor bonding by macro structure is difficult to work. Has been pointed out.

The heat absorption and heat transfer blocking mechanism of the heat shielding paint is as follows. Heat-resistant ceramic paints mainly use ceramic materials with excellent functions of reflecting heat rays in the infrared region, suppressing absorption of visible and ultraviolet rays, radiating absorbed heat, and suppressing conduction and convection of absorbed heat. In addition, it seems that the heat shielding effect is achieved by appropriately designing the structure of the coating film. Such heat shielding coatings are disclosed in Korean Unexamined Patent Publication Nos. 10-2002-50708, 10-2004-43612, 10-2004-465096, 10-2007-87944, and Japanese Unexamined Patent Publication. US Pat. No. 63-29712, Republic of Korea Patent Publication No. 10-2003-58174. However, foreign advanced companies that possess advanced technology for high temperature heat-shielding paints retain most of their know-how for compositions for heat-shielding paints and do not apply for patents or apply for patents. In many cases, only the application method of the composition and the effect of the composition are described and applied. Therefore, there is little technology known in Korea for the high temperature heat-shielding coating composition.

Looking at the properties of conventional high temperature heat insulating paints that are imported from foreign countries and sold on the market, the high temperature heat shielding effect is achieved to some extent. Problems often occurred such as development, release of the coating film from the surface of the material, and generation of holes in portions of the coating film. This problem may be regarded as a phenomenon that the bonding strength between the ceramic paints is weak at high temperatures, the bonding of the coating film is broken. In the case of the existing medium and low temperature heat shielding paints, organic polymer resins are used, and thus organic binders, dispersants, and binders are commonly used to enhance the bonding strength of the coating film. Since organic materials cannot be used due to the problem, the coating film should be formed using only pure inorganic ceramic materials. In this case, the problem of weak bonding strength of the heat shielding coating film has been a serious problem. Occurred. Conventionally, as a binder of inorganic ceramic paints, sodium silicate, potassium silicate, lithium silicate, colloidal silica, sodium silicate, potassium silicate, silicon compound, organosiloxane, tetraalkoxy silane, metal alkoxide, Al ₂ O ₃ -MgO -SiO ₂ -Na ₂ OK ₂ O and the like, and the binder is disclosed in Korean Patent 2000-67313, Japanese Patent Application Laid-Open No. 10-25431, Korean Patent 2000-10246, Korean Patent 2000-43675 and the like. have. However, the binder used in the conventional heat shielding ceramic paint has a weak bonding force at a high temperature, so that peeling of the coating film, distortion or hole generation, softening or vitrification of the coating film occur seriously. When Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O is used as a binder, it has been reported that the bonding strength is relatively better than that of other binders, but Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ Even in the case of O binders, the long term exposure to high temperatures may cause the bonding strength to be weak. The present inventors have repeated tests on a number of binders to find a binder having a higher binding strength than Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O as a binder of a ceramic material, thereby expressing the maximum binding force at a high temperature. The binder composition was found to complete the present invention.

Therefore, the inventors of the present invention have studied various combinations of inorganic binders capable of imparting bonding strength to heat shielding inorganic ceramic materials, and have excellent compatibility with conventional inorganic heat shielding ceramic materials, and at the same time, vitrification and softening do not occur at high temperatures. The present invention has been completed by searching numerous inorganic binder materials.

The present invention is to provide a binder composition for solving the problem that the thermal barrier paint used in the conventional extremely high temperature is weak bond strength when exposed to high temperature for a long time, and excellent compatibility with the heat shield inorganic ceramic material at high temperature, vitrification And to provide an inorganic ceramic-based binder composition does not occur softening phenomenon.

Hereinafter, the configuration and effects of the present invention will be described in detail.

As described above, the binder of the present invention is composed of Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O, tungsten carbide, sodium silicate (Na ₂ · ₃ SiO ₂ ), silicon dioxide.

Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O has excellent bonding strength at high temperatures, tungsten carbide is a ceramic-based material that forms a strong film at high temperatures, and sodium silicate (Na ₂ · 3SiO ₂ ) and silicon dioxide The synergistic effect of each other serves to fill the torsion or holes of the heat shielding coating film which may be foamed at a high temperature to occur at a high temperature. However, when excessive addition of sodium silicate and silicon dioxide can deform or destroy the coating film while foaming at a high temperature, sodium silicate and silicon dioxide are added in small amounts. On the contrary, when Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O and tungsten carbide are used as the binder, the bonding strength is excellent, but it is difficult to fill the pores due to warping or hole generation of the coating film which may occur at high temperatures. Difficult problems arise. That is, the present invention is based on Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O and tungsten carbide as a binder component, the defects (holes) of the coating film that can occur physically at high temperature It is to exert a trade-off effect that is smoothed by the foaming action of and silicon dioxide.

Specific binder content is Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O / tungsten carbide = 8/2 (weight ratio) 95-98 parts by weight of sodium silicate (Na ₂ · ₃ SiO ₂ ) / silicon dioxide It is preferred to include 2 to 5 parts by weight of = 1/1 (weight ratio), more preferably Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O / tungsten carbide = 8/2 (weight ratio) mixture 100 weight When the part contains 2 parts by weight of a mixture of sodium silicate (Na ₂ · ₃ SiO ₂ ) / silicon dioxide = 1/1 (weight ratio), it showed the best binding force. The addition amount of sodium silicate (Na ₂ · 3SiO ₂ ) / silicon dioxide = 1/1 mixture should be carefully selected by repeated tests according to the type of heat shield composition, and sodium silicate (Na ₂ · 3SiO ₂ ) / silicon dioxide When the content of the = 1/1 mixture exceeds 5% of the total solid weight of the binder, the binding effect is reduced. In addition, the amount of the binder is preferably added 5 to 10 parts by weight based on 100 parts by weight of the total heat shield composition, more preferably 7 to 8 parts by weight.

Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O / tungsten carbide = 8/2 The mixture and silicon dioxide are added in the form of solid particulates, and sodium silicate (Na ₂ · 3SiO ₂ ) is added as a 50% by weight aqueous solution. Add. In the manufacturing method of the binder, 95-98 parts by weight of Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O / tungsten carbide = 8/2 mixture was added to a dynomil loaded with glass beads, and sodium silicate (Na ₂ 3SiO ₂ ) 2 to 5 parts by weight of a 50% by weight aqueous solution and 1 to 2.5 parts by weight of silicon dioxide are added and dispersed at 2,500 rpm for 3 hours. The binder prepared by the above method is added 5 to 10 parts by weight based on 100 parts by weight of the heat shield composition.

As described above, in the case of adding 5 to 15 parts by weight of the binder of the present invention with respect to 100 parts by weight of the heat shielding paint, the heat shielding property is superior to the existing products, but the bonding strength of the coating film is extremely superior to the existing products. Even when exposed to high temperature for a long time, peeling of the coating film, generation of distortion, holes, and dropping were not observed. The composition ratio of the binder composition may be partially added or subtracted as the case may be, and is not necessarily limited to the content range of the composition described above.

Example 1

95 parts by weight of the mixture of Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O / tungsten carbide = 8/2 and sodium silicate (Na ₂ · A 5 parts by weight binder of 3SiO ₂ ) / silicon dioxide = 1/1 mixture was prepared.

[Example 2]

98 parts by weight of the mixture of Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O / tungsten carbide = 8/2 and sodium silicate (Na ₂ · A 2 parts by weight binder of 3SiO ₂ ) / silicon dioxide = 1/1 mixture was prepared.

TABLE 1 Composition ratio of binder (parts by weight)

ingredient Example 1 Example 2 Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O 76 78.4 Tungsten carbide 19 19.6 50 wt% aqueous solution of sodium silicate (Na ₂ · 3 SiO ₂ ) 5 2 Silicon dioxide 2.5 One

Manufacture of heat shield composition

The heat shield composition is the same method as the binder manufacturing method of the aqueous ceramic heat shield composition containing 50% by weight of the titanium oxide / antimony dichromate / SiC / SiO ₂ -Al ₂ O ₃ = 1/1/1/1 (weight ratio) mixture As prepared, the glass beads were dispersed by dispersing at 2,500 rpm for 3 hours in a dynomill, and detailed components are shown in Table 2 below (unit: parts by weight).

TABLE 2 Composition ratio of heat shield composition

Ingredient Parts by weight Titanium oxide 12.5 Dichromate Antimony 12.5 SiC 12.5 SiO ₂ -Al ₂ O ₃ 12.5 water 50

As shown in Examples 3, 4, 5 and 6, 7 parts by weight and 12 parts by weight of the binder composition according to the present invention prepared in Examples 1 and 2 were mixed with respect to 100 parts by weight of the heat shield composition. A heat shield composition according to the present invention was prepared.

Example 3

A composition prepared by adding 7 parts by weight of the binder composition of Example 1 to 100 parts by weight of the heat shield composition.

Example 4

A composition prepared by adding 12 parts by weight of the binder composition of Example 1 to 100 parts by weight of the heat shield composition.

Example 5

A composition prepared by adding 7 parts by weight of the binder composition of Example 2 to 100 parts by weight of the heat shield composition.

Example 6

A composition prepared by adding 12 parts by weight of the binder composition of Example 2 to 100 parts by weight of the heat shield composition.

The composition prepared in Example 3, 4, 5, 6 was hand-coated with a 10 MIL blade on a 1 mm ceramic sheet, dried at 200 ° C. for 3 hours, and then left at room temperature for 1 day to measure physical properties. In Comparative Example, a heat-shielding paint sold on the market was hand-coated with 10 MIL blades on a 1 mm ceramic sheet, dried at 200 ° C. for 3 hours, and then used at room temperature for 1 day to prepare a sample. The coating film thickness of the comparative example was 1.65 mm. The thickness of the heat shield coating film was 1.5 mm in Example 3, 1.55 mm in Example 4, 1.7 mm in Example 5, and 1.75 mm in Example 6. In the measurement of the physical properties, the thermal insulation film was exposed to a heat source at 1000 ° C. for 10 minutes, and then the temperature of the ceramic sheet surface was measured by a thermoelectric thermometer, and the bonding force of the coating film was peeling, warping and holes. In comparison with the comparative example, the occurrence of the drooping phenomenon was shown as defective, normal, good, and very good. The above evaluation results are shown in Table 3.

[Table 3] Evaluation Results

Evaluation item Evaluation condition Example 3 Example 4 Example 5 Example 6 Comparative example Heat shield 10 minutes exposure at 1000 ℃ 500 ℃ 480 ℃ 485 ℃ 465 ℃ 550 ℃  cohesion Peeling phenomenon Not Occurred Not Occurred Not Occurred Not Occurred Observation Twist / Hall Not Occurred Not Occurred Not Occurred Not Occurred Observation Dripping Not Occurred Not Occurred Not Occurred Not Occurred Observation

* Comparative Example used a sample prepared by commercially available heat-shielding paint on the 1 mm ceramic sheet with a 10 MIL blade, dried for 3 hours at 200 ℃, then left at room temperature for 1 day. The coating film thickness of the comparative example was 1.65 mm. The evaluation result was carried out relative evaluation based on the comparative example.

As can be seen from the results of Table 3, the heat shielding paint including the binder of the present invention was superior to the heat shielding paint, while the heat shielding, it was found that the bonding force is excellent. In the peeling phenomenon, the peeling phenomenon was partially observed when exposed at 1000 ° C. for 10 minutes due to the weakness of the bonding force in the existing product, but the peeling phenomenon was not observed in the heat shielding composition of the present invention, and even in the distortion or hole generation In the case of the product, some distortion or holes occurred, but in the case of the composition of the present invention, there was no problem of distortion or hole generation due to the addition of the inorganic ceramic foam component. In the flow-through phenomenon, the softening phenomenon was observed in some cases, but not in the case of the existing product, but in the heat-shielding paint to which the binder of the present invention was added, no flow-through phenomenon was observed due to the strong binding force of the binder.

As described above, the heat-shielding water-based ceramic coating composition of the present invention is excellent in heat shielding at a high temperature, it can be seen that the bonding strength is significantly superior to conventional heat shielding paint.

Claims (4)

In a heat-shielding aqueous ceramic coating composition having excellent bonding strength at high temperature, 5 to 15 parts by weight of the binder component based on 100 parts by weight of the heat shield composition, The heat shield composition is composed of 50% by weight of solid content and 50% by weight of water of titanium oxide / antimony dichromate / SiC / SiO ₂ -Al ₂ O ₃ = 1/1/1/1, The binder component is Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O / tungsten carbide = 8/2 95-98 parts by weight of the mixture, sodium silicate (Na ₂ · 3SiO ₂ ) 50% by weight aqueous solution 2-5 Part by weight, 1 to 2.5 parts by weight of silicon dioxide, heat-shielding aqueous ceramic coating composition characterized in that the mixture. The laminated body which apply | coated the heat-shielding aqueous ceramic coating composition of Claim 1 to the outer surface of the object, and formed the heat shielding coating film on the outer surface of the object. The laminate according to claim 2, wherein the object is any one of a film, a raw material storage tank, a fluid transfer hot pipe, an aircraft, a spacecraft, an outer wall of an electric furnace, and an outer wall of a fireproof furnace. In the method of manufacturing the heat-shielding aqueous ceramic coating composition of claim 1, Titanium oxide / antimony dichromate / SiC / SiO ₂ -Al ₂ O ₃ = 1/1/1/1 2,500 heat shielding composition consisting of 50% by weight of solids and 50% by weight of water in dinomil loaded with glass beads After dispersing at rpm for 3 hours, 5 to 15 parts by weight of the binder is added to 100 parts by weight of the heat-shielding composition to prepare an additional 1 hour at 2,500 rpm. The binder is Al ₂ O ₃ -MgO-SiO ₂ -Na ₂ OK ₂ O / tungsten carbide = 8/2 weight ratio mixture of 95 to 98 parts by weight and sodium silicate (Na ₂ · 3SiO ₂ ) 50% by weight aqueous solution 2 ~ 5 parts by weight, silicon dioxide 1 to 2.5 parts by weight of the manufacturing method of the heat-shielding aqueous ceramic coating composition, characterized in that.