KR101797751B1 - Preparing method of zirconia sol and zirconia sol prepared thereby - Google Patents

Abstract

The present invention relates to a method for producing zirconia, and zirconia sol produced thereby. According to an embodiment of the present invention, the method for producing the zirconia sol comprises the following steps: adding an alkaline buffer solution into a zirconium precursor so as to prepare a zirconium gel dispersion solution; and hydrothermally synthesizing zirconia from the zirconium gel dispersion solution so as to produce sol containing zirconia. According to the present invention, it is possible to produce thin films with high refractive index as well as excellent chemical resistance and mechanical properties by using the zirconia sol.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zirconia sol and a zirconia sol prepared by the same,

The present invention relates to a process for the production of zirconia and a zirconia sol prepared thereby.

Since zirconia sol has excellent physical properties such as high dielectric constant, high refractive index, chemical resistance and heat resistance, it is actively used in fields such as optical materials, structural materials and protective coating materials. The application range of zirconia sol having such excellent physical properties is required to be electric and electronic materials requiring high purity, and active research for application is under way.

As a method for producing a zirconia sol, a method of heating hydrolysis of a zirconium salt aqueous solution, a method of adding hydrogen peroxide solution to a zirconium salt aqueous solution, a method of heating zirconium hydroxide in a basic region, and a hydrothermal synthesis method are known. Since most of the zirconium salts are hydrolyzed and heated in the acidic region, the reaction system becomes unstable and tends to cause gelation due to the generated particles. In addition, in the method of hydrolyzing a zirconium salt in an alkali region using an alkali hydroxide, a large amount of precipitate is generated with the elapse of time although a particle is generated, and the zirconium salt becomes a slurry form, and a completely stable sol can not be obtained. In addition, the hydrothermal synthesis method can not always synthesize a constant level of sol because of varying pH range depending on zirconium salt and alkaline solution for obtaining zirconium hydroxide.

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a method for producing zirconia excellent in dispersibility of zirconia particles in a state where the pH change is small, and a zirconia sol produced thereby.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to one embodiment, there is provided a method for preparing a zirconium gel dispersion, comprising: preparing a zirconium gel dispersion by adding an alkaline buffer solution to the zirconium precursor; And hydrothermally synthesizing zirconia from the zirconium gel dispersion to prepare a sol containing zirconia.

According to one aspect, the pH difference between the zirconium gel dispersion and the zirconia-containing sol may be 0.1 to 1.

According to one side, wherein the zirconium precursor is zirconium acetate _{^{(Zr x + · x CH 3}} COOH), zirconium hydroxide (Zr (OH) _4), zirconium chloride (ZrCl _2), zirconium oxychloride (ZrOCl _2), zirconyl zirconyl chloride octa hydrate _{(ZrOCl 2 · 8H 2 O)} , zirconium tetrachloride (ZrCl _4), zirconium nitrate _{(ZrO (NO 3) 2)} , zirconium sulfate _{(Zr (SO 4) 2)} , zirconium carbonate ammonium (NH _{4 ) 2 [Zr (CO 3)} 2 (OH) 2], zirconium carbonate, potassium _{K 2 [Zr (CO 3)} 2 (OH) 2], zirconyl nitrate hydrate _{(ZrO (NO 3) 2 ·} x H 2 O ), zirconium (IV) tert - butoxide _{(Zr (OC 4 H 9)} 4, ZrTB) and aryloxy ethyl zirconium _{(ZrO a (CH 3 COO)} b) ( a is 0 <a <2, b is 0 < b < 4, and 2a + b = 4).

According to one aspect, the zirconium precursor may be 10 wt% to 20 wt% of the zirconium gel dispersion.

According to one aspect, the alkaline buffer solution may be selected from the group consisting of potassium bicarbonate, ammonium acetate, sodium acetate, potassium acetate, ammonium phosphate, sodium phosphate phosphate, potassium phosphate, ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, sodium carbonate, potassium carbonate, triethylammonium carbonate, And may include at least one selected from the group consisting of triethylammonium bicarbonate, ammonium chloride, and ammonium hydroxide.

According to one aspect, the alkaline buffer solution may be 40 wt% to 60 wt% of the zirconium gel dispersion.

According to one aspect, the hydrothermal synthesis may be performed at a temperature of 150 ° C to 280 ° C for 1 hour to 24 hours.

According to one aspect, the pH of the zirconia-containing sol prepared after the hydrothermal synthesis may be 8 to 12.

According to another embodiment, there is provided a zirconia sol prepared by a method for producing a zirconia sol according to an embodiment, wherein zirconia particles having an average primary particle size in the range of 1 nm to 20 nm are dispersed.

According to one aspect, the zeta potential of the zirconia sol may be from -10 mV to -30 mV.

According to one aspect, the zirconia sol may further include an acidic polymer dispersant.

According to one aspect, the acidic polymeric dispersant is selected from the group consisting of solsperse 5000 (trade name), solsperse 8000, solsperse 11200, solsperse 12000, solsperse 13300, solsperse 20000, solsperse 22000, solsperse (trade name), Lubrizol corp. 2600, solsperse 27000, solsperse 54000, CX4320 (trade name), BASF (trade name), DFKA-4330, BYK-106 (trade name) KD-6 (trade name), sodium diphosphate, sodium polyacrylate, sodium methacrylate, and the like of BYK-161, BYK-163 and CRODA, Polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, and polyoxyethylene sorbitan trioleate &Lt; RTI ID = 0.0 &gt; May also include any one of them.

According to one aspect, the zirconia particles have a 10% cumulative value average particle diameter (D ₁₀ ) in a range of 5 nm to 30 nm, a 50% cumulative value average particle diameter (D ₅₀ ) in a range of 10 nm to 40 nm, (D ₉₅ ) may range from 30 nm to 90 nm.

According to one aspect, the pH of the zirconia sol may be 7 to 10.

According to the method for producing zirconia according to an embodiment of the present invention, zirconia particles having a predictable pH can be synthesized. The zirconia particles in the zirconia sol can be uniformly dispersed in the dispersion medium, uniformly dispersed in the dispersion medium, less aggregated and can be maintained in a stable state without forming a long-term precipitation, and thus the zirconia sol having high storage stability can be produced. The prepared zirconia sol can be used to prepare a stable zirconia sol in a pH range from neutral to slightly alkaline. Furthermore, by using such a zirconia sol, a thin film having a high refractive index and excellent mechanical properties and chemical resistance can be produced.

1 is a flow chart illustrating a process for producing a zirconia sol according to an embodiment of the present invention.
Fig. 2 is a photograph ((a), (b), and (c) illustrate the transparency after curing the zirconia sol according to Examples 4 to 6 of the present invention.
3 is a graph showing D ₁₀ , D ₅₀ and D ₅₀ particle sizes of zirconia particles in the zirconia sol of Examples 4 to 9 of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, terms used in this specification are terms used to appropriately express the preferred embodiments of the present invention, which may vary depending on the user, the intention of the operator, or the practice of the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification. Like reference symbols in the drawings denote like elements.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

Hereinafter, the method for producing zirconia of the present invention and the zirconia sol produced thereby will be described in detail with reference to examples and drawings. However, the present invention is not limited to these embodiments and drawings.

According to one embodiment, there is provided a method for preparing a zirconium gel dispersion, comprising: preparing a zirconium gel dispersion by adding an alkaline buffer solution to the zirconium precursor; And hydrothermally synthesizing zirconia from the zirconium gel dispersion to prepare a sol containing zirconia.

According to one aspect of the present invention, the zirconia-containing sol prepared by the above-described method for producing a zirconia sol is a solution in which uniform zirconia particles are dispersed in a colloidal state, wherein a zirconium precursor is used as a starting compound to form an alkali metal hydroxide and an alkaline buffer solution Can be precipitated and produced.

According to the method for producing a zirconia sol according to an embodiment of the present invention, zirconia particles having a predictable pH can be synthesized. The zirconia particles in the zirconia sol can be uniformly dispersed in the dispersion medium, uniformly dispersed in the dispersion medium, less aggregated and can be maintained in a stable state without forming a long-term precipitation, and thus the zirconia sol having high storage stability can be produced.

1 is a flow chart illustrating a process for producing a zirconia sol according to an embodiment of the present invention. Referring to FIG. 1, a process for preparing a zirconia sol according to an embodiment of the present invention includes preparing a zirconium gel dispersion (110); And a hydrothermal synthesis step (120).

According to one aspect, the zirconium gel dispersion preparation step 110 may be to prepare a zirconium gel dispersion by adding an alkaline buffer solution to the zirconium precursor.

According to one side, wherein the zirconium precursor is zirconium acetate (Zr ^{x +} and x CH ₃ COOH), zirconium hydroxide (Zr (OH) _4), zirconium chloride (ZrCl _2), zirconium oxychloride (ZrOCl _2), zirconyl zirconyl chloride octa hydrate (ZrOCl ₂ and 8H ₂ O), zirconium tetrachloride (ZrCl _4), zirconium nitrate _{(ZrO (NO 3) 2)} , zirconium sulfate _{(Zr (SO 4) 2)} , zirconium carbonate ammonium (NH _{4 ) 2 [Zr (CO 3)} 2 (OH) 2], zirconium carbonate, potassium _{K 2 [Zr (CO 3)} 2 (OH) 2], zirconyl nitrate hydrate (ZrO (NO _{3) 2} and x H ₂ O ), zirconium (IV) tert - butoxide _{(Zr (OC 4 H 9)} 4, ZrTB) and aryloxy ethyl zirconium _{(ZrO a (CH 3 COO)} b) ( a is 0 <a <2, b is 0 < b < 4, and 2a + b = 4).

According to one aspect, since the zirconium precursor is well soluble in water at a low temperature, water can be basically used as a solvent for precipitation. When water is used solely as a solvent, the precipitation temperature and dielectric constant value are too high. Therefore, in addition to water, a solvent such as ethanol, ethyl alcohol, 1-propyl alcohol, 2-propyl alcohol, And at least one selected from the group consisting of &lt; RTI ID = 0.0 &gt; As the concentration of water in the preparation of the zirconia particles is increased, the particle size becomes finer and the cohesive force of the fine particles becomes stronger. Therefore, the content of the water-alcohol mixture may be greatly affected by the degree of coagulation. The average particle diameter of the zirconia particles to be produced, the content of the zirconia precursor, the cleaning and concentration of the resulting sol, the separation and purification of the solvent, and the economic efficiency due to the recycling.

According to one aspect, the zirconium precursor may be 10 wt% to 20 wt% of the zirconium gel dispersion. If the zirconium precursor is less than 10% by weight, the yield of the zirconium precursor is lowered and the transparency of the zirconia sol is lowered. If the zirconium precursor is more than 20% by weight, the zirconia sol may have an uneven particle size, There is a tendency to increase.

According to one aspect, the alkaline buffer solution may be selected from the group consisting of potassium bicarbonate, ammonium acetate, sodium acetate, potassium acetate, ammonium phosphate, sodium phosphate phosphate, potassium phosphate, ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, sodium carbonate, potassium carbonate, triethylammonium carbonate, And may include at least one selected from the group consisting of triethylammonium bicarbonate, ammonium chloride, and ammonium hydroxide.

According to one aspect, the alkaline buffer solution may be 40 wt% to 60 wt% of the zirconium gel dispersion. If the alkaline buffer solution is less than 40 wt% of the zirconium gel dispersion, it may affect the morphology and pH of the zirconia particles to cause growth of the zirconia particles to a proper shape. When the alkaline buffer solution is more than 60 wt%, uniform zirconia The formation of particles is difficult, and the shape and pH of the particles may be adversely affected.

According to one aspect, the alkali metal hydroxide may be further added while sufficiently stirring the zirconium precursor. The alkali metal hydroxide may include at least one selected from the group consisting of sodium hydroxide (NaOH), potassium hydroxide (KOH), and lithium hydroxide (LiOH).

According to one aspect, the hydrothermal synthesis step 120 is a step of hydrothermally synthesizing zirconia from the zirconium gel dispersion to prepare a sol containing zirconia.

According to one aspect, the zirconium gel dispersion may further include cleaning (not shown) before hydrothermal synthesis. The cleaning method may be performed using an ultrafiltration membrane separation method, a filtration separation method, a centrifugation filtration method, an ion exchange resin method, or the like which can remove anions, cations or salts. The ion exchange resin method is preferable because it can effectively lower the ion concentration after cleaning. In this case, it may be more efficient to perform the cleaning by the ultrafiltration membrane method and then the cleaning by the ion exchange resin method. As the ion exchange resin, a cation-anion complex exchange resin may be used, or a cation exchange resin and an anion exchange resin may be used sequentially.

According to one aspect, the hydrothermal synthesis may be performed using an autoclave apparatus.

According to one aspect, the hydrothermal synthesis may be performed at a temperature of 150 ° C to 280 ° C for 1 hour to 24 hours. When the hydrothermal synthesis temperature is less than 150 ° C. and the hydrothermal synthesis time is less than 1 hour, it is difficult to obtain a zirconia sol having a desired particle size because the particle growth is required for a long period of time, and the hydrothermal synthesis temperature is more than 280 ° C., In the case of exceeding 24 hours, the particle growth time may be accelerated, but the particle size dispersion may become uneven, which may generate large particles. Thus, by hydrothermal synthesis, a zirconia sol in which zirconia particles excellent in dispersibility and stability are dispersed as a non-agglomerated substance having a small average particle size and a uniform particle size distribution can be produced.

According to one aspect of the present invention, zirconia-containing sol can be used immediately after the hydrothermal synthesis, but it may further include a step (not shown) of performing cleaning with pure water using an ultrafiltration device or the like have. As a result, unnecessary salts can be removed, and a high purity alkaline zirconia sol can be obtained

According to one aspect, the pH of the zirconia-containing sol prepared after the hydrothermal synthesis may be 8 to 12. It is possible to obtain an alkaline zirconia sol having improved stability as a zirconia particle synthesized at a predictable alkaline pH.

According to one aspect, the pH difference between the zirconium gel dispersion and the zirconia-containing sol may be 0.1 to 1. The zirconia particles in the zirconia sol produced after hydrothermal synthesis of the present invention are less aggregated and can be maintained in a stable state without forming a long-term precipitation. The zirconia sol prepared after the hydrothermal synthesis can be stably existed for more than 3 months under the condition of 50.

According to another embodiment, there is provided a zirconia sol prepared by a method for producing a zirconia sol according to an embodiment, wherein zirconia particles having an average primary particle size in the range of 1 nm to 20 nm are dispersed.

According to one aspect, when the average primary particle diameter of the zirconia particles is less than 1 nm, crystals of zirconia become insufficient and the refractive index tends to decrease. When the average primary particle diameter exceeds 20 nm, the zirconia particles can be obtained without using the present invention, Dispersion stability and transparency are deteriorated, and formation of a film which requires strength or transparency of the film becomes insufficient. The average particle size of zirconia particles can be obtained by measuring the particle size of 50 particles when a transmission electron microscope (TEM) photograph is taken. The average particle diameter of the zirconia particles can be measured by a dynamic light scattering method.

According to one aspect, a zeta potential, which means a potential difference between a shear boundary and a bulk solution, is often used as an index indicating the degree of surface charge of colloidal particles suspended in a liquid. The zeta potential of the zirconia sol may be from -10 mV to -30 mV. In the zeta potential range of the above range, the repulsive force between the zirconia particles generated is maximized, and the optimum particle dispersion condition can be obtained. Accordingly, the zirconia particles have excellent dispersion stability in the zirconia sol.

According to one aspect, the zirconia sol may further include an acidic polymer dispersant.

According to one aspect, the acidic polymeric dispersant is selected from the group consisting of solsperse 5000 (trade name), solsperse 8000, solsperse 11200, solsperse 12000, solsperse 13300, solsperse 20000, solsperse 22000, solsperse (trade name), Lubrizol corp. 2600, solsperse 27000, solsperse 54000, CX4320 (trade name), BASF (trade name), DFKA-4330, BYK-106 (trade name) KD-6 (trade name), sodium diphosphate, sodium polyacrylate, sodium methacrylate, and the like of BYK-161, BYK-163 and CRODA, Polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, and polyoxyethylene sorbitan trioleate &Lt; RTI ID = 0.0 &gt; May also include any one of them.

According to one aspect, the zirconia particles of the zirconia sol containing the acidic polymer dispersant have a 10% cumulative value average particle diameter (D ₁₀ ) in a range of 5 nm to 30 nm, a 50% cumulative value average particle diameter (D ₅₀ ) To 40 nm, and a 95% cumulative value average particle diameter (D ₉₅ ) in the range of 30 nm to 90 nm. D ₁₀ represents the particle diameter, which means that the number of particles of a particle size of less than 10% of the entire particles, and D ₅₀ represents the particle diameter, which means that the number of particles of a particle size of less than 50% of the entire particles, and D ₉₀ Indicates a particle diameter which means that the number of particles having a particle diameter equal to or smaller than 90% of the total number of particles.

According to one aspect of the present invention, when the average particle diameter (D ₁₀ ) is less than 5 nm, the zirconia particles are smaller in size than the primary particles of the zirconia particles and are not dispersed in the liquid phase. And when the average particle diameter (D ₅₀ ) is less than 10 nm and the average particle diameter (D ₉₅ ) is less than 30 nm, the stability of the zirconia sol decreases and the content of the dispersant tends to increase relatively, (D ₁₀ ) of more than 30 nm, the average particle diameter (D ₅₀ ) of more than 40 nm, and the average particle diameter (D ₉₅ ) of more than 90 nm, the dispersion stability and transparency Can be degraded.

According to one aspect, the pH of the zirconia sol may be 7 to 10. By adjusting the dispersing agent content of the acidic polymer, stable zirconia sol can be obtained in a pH range of 7 to 10 from neutral to weakly alkaline.

According to one aspect, the zirconia sol of the present invention can maintain a uniform particle size distribution, less aggregation, and stable state without formation of a long-term precipitation.

Hereinafter, the present invention will be described in detail with reference to the following examples and comparative examples. However, the technical idea of the present invention is not limited or limited thereto.

[ Example  One]

Zirconium hydroxide (Zr (OH) ₄ ) was prepared using 2 M of oxychloride solution and 2 M of sodium hydroxide (NaOH) solution. 800 g of ultrapure water was diluted with a buffer solution of 10 g of ammonium bicarbonate to a concentration of 0.5 M. The reaction was carried out at 180 占 폚 for 6 hours to 10 hours using a high-pressure reactor. Subsequently, when the reaction proceeded using an autoclave vessel, the reaction was carried out at 180 ° C for 10 hours to 14 hours.

[ Example  2]

A zirconia sol was prepared in the same manner as in Example 1, except that sodium bicarbonate (SBC) was added as an alkaline buffer solution.

[ Example  3]

A zirconia sol was prepared in the same manner as in Example 1, except that 10 g of 5 g each of ammonium bicarbonate (ABC) and sodium bicarbonate (SBC) was added as an alkaline buffer solution.

Table 1 shows the pH of the solution before hydrothermal synthesis of Examples 1 to 3 of the present invention, the pH of the solution after hydrothermal synthesis, pH as a difference between two pH values, the average primary particle diameter of zirconia particles dispersed in the prepared zirconia sol, Zeta potential of zirconia sol is shown.

Buffer solution pH pH Primary particle size
(nm) Zeta potential
(mV) Kinds density
(mol) Before hydrothermal synthesis
solution After hydrothermal synthesis
solution Example 1 ABC 0.15 9.41 9.29 0.12 10.4067 -15 Example 2 SBC 0.15 9.41 9.03 0.38 10.6916 -21.4 Example 3 ABC
+ SBC 0.15 9.41 8.88 0.53 11.5601 -23.29

* ABC: ammonium bicarbonate, SBC: sodium bicarbonate

Referring to Table 1, it can be seen that the zirconia sols of Examples 1 to 3 of the present invention had a pH difference of less than 1 and a smaller pH difference than the zirconium precursor before hydrothermal synthesis. In addition, it can be confirmed that zirconia particles dispersed in the prepared zirconia sol are generally uniform. It can also be confirmed that the zeta potential of the zirconia sol is stable within the range of -15 mV to -25 mV.

As a result, it can be confirmed that the zirconia sols of Examples 1 to 3 can synthesize an alkaline zirconia sol with a small pH difference.

[ Example  4]

The zirconia sol prepared in Example 1 was dried to prepare zirconia powder. 10% by weight of solsperse 27000 (trade name) of Lubrizol Corp. (Lubrizol Corp., USA) as an acidic polymer dispersant was added to 60 wt% of ultrapure water to prepare a mixed solution. 30% by weight of the zirconia powder was added to the mixed solution to prepare a final zirconia sol.

[ Example  5]

A zirconia sol was prepared in the same manner as in Example 4, except that 20 wt% of solsperse 27000 (trade name) was added as an acidic polymer dispersant.

[ Example  6]

A zirconia sol was prepared in the same manner as in Example 4, except that 30 wt% of solsperse 27000 (trade name) was added as an acidic polymer dispersant.

[ Example  7]

A zirconia sol was prepared in the same manner as in Example 4, except that solsperse 54000 (trade name) was added as an acidic polymer dispersant.

[ Example  8]

A zirconia sol was prepared in the same manner as in Example 4 except that 20% by weight of sodium methacrylate was added as an acidic polymer dispersant.

[ Example  9]

A zirconia sol was prepared in the same manner as in Example 4 except that 20% by weight of sodium polyacrylate was added as an acidic polymer dispersant.

Table 2 shows the kind, content, final zirconia sol pH and final particle diameter (D ₁₀ , D ₅₀ , D ₉₅ ) of the final zirconia sol of Examples 4 to 9 of the present invention.

Acidic polymer dispersant content
(weight%) pH Particle size
(nm) D ₁₀ D ₅₀ D ₉₅ Example 4 Solsperse 27000 10 - 22.1 34.9 86.8 Example 5 Solsperse 27000 20 - 19 29.8 76.1 Example 6 Solsperse 27000 30 - 16.8 26 64 Example 7 Solsperse 54000 20 7.73 8.2 12.4 36.1 Example 8 Sodium methacrylate 20 8.26 9.3 13.8 35.1 Example 9 Sodium polyacrylate 20 8.03 9.3 13.7 34.6

As a result, it was confirmed that zirconia sol was effectively produced even when an acidic polymer dispersant was added as in Examples 4 to 9.

Fig. 2 is a photograph ((a), (b), and (c) illustrate the transparency after curing the zirconia sol according to Examples 4 to 6 of the present invention. Referring to FIGS. 2 (a) to 2 (c), transparency increases as the content of the acidic polymer dispersant Solsperse 27000 increases. Thus, it can be seen that a zirconia sol having excellent transparency and dispersibility can be produced under the optimum dispersant content.

3 is a graph showing D ₁₀ , D ₅₀ and D ₅₀ particle sizes of zirconia particles in the zirconia sol of Examples 4 to 9 of the present invention. 3 and Table 2, when Solsperse 27000 was used as the acidic polymer dispersant, the 10% cumulative value D ₁₀ of the particle size, the 50% cumulative value D ₅₀ of the particle size, and the 95% cumulative value D _{95 of the} particle size decreased as the content increased. . The zirconia content in the zirconia sols of Examples 4 to 9 is 20% by weight. When the zirconia content is 20% by weight, it is found that the optimum dispersant content is optimal in the case of solsperse 27000 of zirconia powder by 30% by weight.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the equivalents of the appended claims, as well as the appended claims.

Claims (14)

Preparing a zirconium gel dispersion by adding an alkaline buffer solution to the zirconium precursor;
Hydrothermally synthesizing zirconia from the zirconium gel dispersion to prepare a sol containing zirconia;
Drying the zirconia-containing sol to produce zirconia powder; And
Adding the zirconia powder to a solution containing an acidic polymeric dispersant;
&Lt; / RTI &gt;
The method according to claim 1,
Wherein the pH difference between the zirconium gel dispersion and the zirconia-containing sol is 0.1 to 1.
The method according to claim 1,
The zirconium precursor may be selected from the group consisting of zirconium acetate (Zr ^{x +} x CH ₃ COOH), zirconium hydroxide (Zr (OH) ₄ ), zirconium chloride (ZrCl ₂ ), zirconium chloride (ZrOCl ₂ ), zirconyl chloride octahydrate (ZrOCl ₂ and 8H ₂ O), zirconium tetrachloride (ZrCl _4), zirconium nitrate _{(ZrO (NO 3) 2)} , zirconium sulfate _{(Zr (SO 4) 2)} , zirconium carbonate ammonium (NH _{4) 2} [Zr _{(CO 3) 2 (OH)} 2], zirconium carbonate, potassium _{K 2 [Zr (CO 3)} 2 (OH) 2], zirconyl nitrate hydrate (ZrO (NO _{3) 2} and x H ₂ O), zirconium ( IV) tert - butoxide _{(Zr (OC 4 H 9)} 4, ZrTB) and aryloxy ethyl zirconium _{(ZrO a (CH 3 COO)} b) (a is 0 <a <2, and, b is 0 <b <4, and , 2a + b = 4). &Lt; / RTI &gt;
The method according to claim 1,
Wherein the zirconium precursor is 10 wt% to 20 wt% of the zirconium gel dispersion.
The method according to claim 1,
The alkaline buffer solution may be at least one selected from the group consisting of potassium bicarbonate, ammonium acetate, sodium acetate, potassium acetate, ammonium phosphate, sodium phosphate, potassium The catalyst is preferably selected from the group consisting of potassium phosphate, ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, sodium carbonate, potassium carbonate, triethylammonium bicarbonate, wherein the zirconia sol comprises at least one selected from the group consisting of bicarbonate, ammonium chloride and ammonium hydroxide.
The method according to claim 1,
Wherein the alkaline buffer solution is 40 wt% to 60 wt% of the zirconium gel dispersion.
The method according to claim 1,
Wherein said hydrothermal synthesis is carried out at a temperature of from 150 DEG C to 280 DEG C for 1 hour to 24 hours.
The method according to claim 1,
Wherein the pH of the zirconia-containing sol prepared after the hydrothermal synthesis is 8 to 12.
A process for producing a zirconia sol according to any one of claims 1 to 8,
A zirconia sol in which zirconia particles having an average primary particle size in the range of 1 nm to 20 nm are dispersed.
10. The method of claim 9,
Wherein the zeta potential of the zirconia sol is from -10 mV to -30 mV.
delete 10. The method of claim 9,
The acidic polymeric dispersant may be selected from the group consisting of solsperse 5000 (trade name), solsperse 8000, solsperse 11200, solsperse 12000, solsperse 13300, solsperse 20000, solsperse 22000, solsperse 26000, solsperse 27000 from Lubrizol corp. BYK-200, BYK-2001, BYK-161 (trade name), BYK-106 (trade name), BYK BYK-163, KD-6 (trade name) of CRODA (Germany), sodium diphosphate, sodium polyacrylate, sodium methacrylate, sorbitan monolaurate Polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, and polyoxyethylene sorbitan trioleate. At least one selected Zirconia sol. &Lt; / RTI &gt;
10. The method of claim 9,
The above-
A 10% cumulative value average particle diameter (D ₁₀ ) in the range of 5 nm to 30 nm,
A 50% cumulative value average particle diameter (D ₅₀ ) in the range of 10 nm to 40 nm,
And a 95% cumulative average particle diameter (D ₉₅ ) in the range of 30 nm to 90 nm.
10. The method of claim 9,
Wherein the zirconia sol has a pH of 7 to 10.

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