KR101752170B1 - Dispersion sol of rutile titanium dioxide and method for preparing the same - Google Patents

Abstract

The present invention relates to a highly dispersed ruthenium-based titanium dioxide nanodispersed sol having a high refractive index and a low photocatalytic property, prepared by milling a titanium precursor in the presence of water and under a sol-gel reaction at room temperature or under hydrothermal conditions, And a method for producing the same.

Description

Technical Field [0001] The present invention relates to a rutile-based titanium dioxide nanodispersion sol and a method for producing the same. BACKGROUND ART < RTI ID = 0.0 >

More particularly, the present invention relates to a rutile-based titanium dioxide nanodispersion sol, and more particularly, to a rutile-based titanium dioxide nanodispersion sol, and more particularly, to a rutile-based titanium dioxide nanodispersion sol which is produced by milling a powdered titanium oxide produced by subjecting a titanium precursor to sol- gel reaction at room temperature or under hydrothermal conditions in the presence of water and acid, A highly dispersed ruthenium-based titanium dioxide nanodispersed sol having high refractive index and low photocatalytic properties, and a method for producing the same.

Titanium dioxide has excellent physical properties such as photocatalyst, high refractive index, whiteness and corrosion resistance, and is actively used in fields such as paint, photocatalyst, cosmetics, and solar cell. The application range of titanium dioxide having such excellent properties is high refractive index Coating materials.

At present, there is no example in which titanium dioxide as described above is prepared with a transparent dispersed sol and a rutile crystal structure. The nanoparticles are mainly prepared as aggregated powder and used as a paint material. In particular, Technologies have been still in the research stage, and even when a transparent dispersion sol is prepared, the concentration is low and the yield and dispersion stability in the manufacturing process are low, which is not economical.

Korean Patent Application No. 1998-28928 discloses that by simply heating titanyl chloride (TiOCl ₂ ) produced from titanium tetrachloride (TiCl ₄ ), the crystalline body spontaneously undergoes uniform precipitation to control the ratio of formation of rutile phase and anatase phase , Or a low temperature such as room temperature to produce a ruta-TiO ₂ ultrafine powder as a monodisperse. However, it has been disclosed that a pure rutile phase The reaction temperature itself is very low because the reaction temperature is very low.

Korean Patent Publication No. 2004-0100732 discloses a method for producing titanium dioxide nanoparticles at a high pressure through a sol-gel method. Titanium dioxide nanoparticles in a stable dispersion state can be prepared by the above method. Such a method has a disadvantage in that the process must be performed at a high temperature and a high pressure, and when the titanium dioxide nanoparticles are dried and redispersed in a dispersion solvent, the particles are agglomerated to form a stable sol. It is not suitable to be applied to an actual process because the solid content must be very low.

Korean Patent Laid-Open Publication No. 2001-0028286 discloses a method for producing a titanium dioxide sol dispersed in water at normal pressure through a sol-gel method. The titanium dioxide sol thus prepared is applicable as a coating film, but has a disadvantage in that the solid content is too low to be used as a filler in a high refractive index hard coating film. Furthermore, when water is removed to increase the solid content, agglomeration between particles occurs and particles become large.

Accordingly, a rutile-based titanium dioxide nano-dispersed sol can be applied to various application fields with high refractive index, excellent transparency, no agglomeration between particles, forming a stable sol, exhibiting a high reaction rate, There is a demand for development of a method for manufacturing a semiconductor device.

Korean Patent Application No. 1998-28928 Korean Patent Publication No. 2004-0100732 Korean Patent Laid-Open Publication No. 2001-0028286

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the problems of the prior art as described above, and it is an object of the present invention to provide a titanium dioxide nanoparticle dispersion, which is rutile and highly dispersed in a solvent, compared with conventional anatase titanium dioxide nanodispersion sol or coagulated rutile titanium dioxide nanoparticle powder. And a process for producing a rutile-based titanium dioxide nano-disperse sol having high refractive index and low photocatalytic property as a dispersed sol.

It is also an object of the present invention to provide a rutile-based titanium dioxide nano-disperse sol having rutile crystal phase and high refractive index and low photocatalytic properties.

According to an aspect of the present invention, there is provided a process for preparing a rutile titanium dioxide nanodispersed sol comprising the steps of:

1) adding a titanium precursor to water or an alcohol in the presence of an acid, and performing a sol-gel reaction at room temperature (23 ± 2 ° C) or under hydrothermal conditions to obtain a titanium dioxide mixed solution;

2) diluting the titanium dioxide mixed solution with alcohol, and then milling to prepare a dispersion sol.

In the step 1), the titanium precursor may be at least one selected from the group consisting of titanium tetraisopropoxide (TTIP) and titanyl chloride (TiOCl ₂ ).

In the step 1), the acid may be at least one selected from the group consisting of nitric acid, sulfuric acid, hydrochloric acid, and acetic acid.

The alcohol used in the step 1) may be one or more selected from the group consisting of methanol, ethanol, propanol, isopropyl alcohol, butyl alcohol and isobutyl alcohol.

In the step 1), the sol-gel reaction may be performed by stirring at room temperature (23 ± 2 ° C) for 70 to 80 hours.

In the step 1), the sol-gel reaction may be performed under stirring (40 to 80 ° C) for 20 to 50 hours.

The water-soluble polymer may be further added in the step 1).

The water-soluble polymer may be at least one selected from non-ionic, anionic, and cationic water-soluble polymers.

The alcohol used in the step 2) may be at least one selected from the group consisting of methanol, ethanol, propanol, isopropyl alcohol, butyl alcohol and isobutyl alcohol.

In the step 2), the bead mill is used for milling, and the zirconia bead size of the bead mill may be 0.3 mm or less.

In the step 2), a dispersant may be further added during milling.

The dispersant may be selected from the group consisting of carboxylic acid salts (RCOO ^- M ⁺ ), sulfonic acid salts (RSO ₃ ^- M ⁺ ), sulfuric acid ester salts (ROSO ₃ ^- M ⁺ ), phosphoric acid ester salts (RPO ₃ ^- Na ^{2 +} ), ammonium halides R4N ⁺ Cl ^-), polyoxyethylene (-OCH ₂ CH ₂ O ^- may be a copolymer of acrylonitrile), Tra-ray lauryl ether, glycolic acid ethoxylate styrene.

The rutile titanium dioxide dispersed sol of the present invention is produced by the process for producing rutile titanium dioxide nanodispersed sol according to the present invention, wherein the titanium dioxide particles have a rutile crystal phase, a single crystal size of 8 to 12 nm, Lt; / RTI >

The titanium dioxide nanodispersion sol may have a solid content of 1 to 50% by weight of titanium dioxide.

According to the present invention, there is provided a process for producing a rutile-type titanium dioxide dispersed sol having high refraction and high transparency, which is simple and has a high reaction speed and is capable of producing a stable dispersion sol without aggregation between particles.

Further, according to the present invention, there is provided a rutile titanium dioxide dispersion sol having a small size and an average particle diameter of a single crystal and having a high degree of dispersion and high transparency.

1 is a schematic view showing a process for producing a titanium dioxide dispersed sol according to Example 1;
2 is a graph showing the results of XRD of the titanium dioxide dispersed sol prepared in Example 1. Fig.
3 is a TEM photograph of the titanium dioxide particles in the titanium dioxide dispersed sol produced by Example 1. Fig.
4 is a photograph of the titanium dioxide dispersed sol prepared by Example 1 and Comparative Example 4. Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to achieve them, will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art. It is to be understood by one of ordinary skill in the art that the scope of the invention is to be fully understood and the invention is only defined by the scope of the claims.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

Hereinafter, a method for producing the rutile-based titanium dioxide nano-disperse sol according to the present invention will be described in detail.

The process for preparing the rutile based titanium dioxide nano-disperse sol according to the present invention may comprise the following steps:

1) adding a titanium precursor to water or an alcohol in the presence of an acid, and performing a sol-gel reaction at room temperature (23 ± 2 ° C) or under hydrothermal conditions to obtain a titanium dioxide mixed solution;

2) diluting the titanium dioxide mixed solution with alcohol, and then milling to prepare a dispersion sol.

In the step 1), the titanium precursor may be at least one selected from the group consisting of titanium tetraisopropoxide (TTIP) and titanyl chloride (TiOCl ₂ ).

In the step 1), the acid may be an organic acid such as formic acid, acetic acid, propionic acid, butyric acid, lactic acid, or citric acid fumaric acid, or an organic acid such as phosphoric acid, sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, chlorosulfonic acid, paratoluenesulfonic acid, , Perchloric acid, and the like, and preferably at least one selected from the group consisting of nitric acid, sulfuric acid, hydrochloric acid, and acetic acid.

The alcohol used in the step 1) may be one or more selected from the group consisting of methanol, ethanol, propanol, isopropyl alcohol, butyl alcohol and isobutyl alcohol.

In the sol-gel reaction in the step 1), the electron density around the titanium dioxide molecule is lowered and the affinity with electrons is increased, so that the reaction with water is facilitated to increase the rate of hydrolysis. It is a process in which polymerization reaction occurs between titanium dioxide particles rapidly. Particularly, the step 1) is carried out in the presence of an acid, thereby not only increasing the reaction rate of the sol-gel reaction but also acting as a peptidizing agent for causing the acid to polymerize.

In the step 1), the sol-gel reaction is preferably carried out by stirring at room temperature (23 ± 2 ° C) for 70 to 80 hours. When the reaction is less than 70 hours, condensation through condensation reaction It is not preferable to increase the particle size or to obtain a monodispersed transparent titanium dioxide dispersed sol. If it exceeds 80 hours, the drying process becomes too long, unreacted materials remain, and it is difficult to obtain a monodispersed transparent titanium dioxide sol The dispersibility is undesirably deteriorated.

In the step 1), the sol-gel reaction is preferably carried out under stirring (40 to 80 ° C) for 20 to 50 hours. When the temperature is outside the range, the crystal growth is not properly performed or the dispersibility is deteriorated A precipitate may be generated even after reprocessing such as physical agitation or the particle size is too large.

The stirring speed in the above step 1) is not particularly limited, but it can be mixed under strong stirring at 500 to 600 rpm, for example.

The water-soluble polymer may be one or more selected from non-ionic, anionic and cationic water-soluble polymers for preventing initial particle size control and aggregation, and specific examples thereof The nonionic water soluble polymer may be polyvinyl alcohol (PVA), polyacrylamine (PAAM), and polyvinyl pyrrolidone (PVP), and the anionic water soluble polymer may be polyacrylic acid, poly (styrenesulfonic acid) (PSSA) , Polyacidic acid (PSiA) and polyphosphoric acid, and the cationic water-soluble polymer may be polyethyleneimine (PEI), polyamine and polyamideamine (PAMAM).

The alcohol used in the step 2) may be at least one selected from the group consisting of methanol, ethanol, propanol, isopropyl alcohol, butyl alcohol and isobutyl alcohol.

In the step (2), the bead mill is used for milling, and the zirconia bead size of the bead mill is preferably 0.3 mm or less. If the bead mill is out of the range, milling is not properly performed.

<Q: The reasons for limiting the size of the zirconia beads are described as optional.

In the step (2), a dispersant may be further added in order to further maximize the effect of milling at the time of milling. Specific examples thereof include a carboxylic acid salt (RCOO ^- M ⁺ ), a sulfonic acid salt (RSO ₃ ^- M ⁺ (ROSO ₃ ^- M ⁺ ), phosphate ester salt (RPO ₃ ^- Na ^{2 +} ), ammonium halide (R ⁴ N ⁺ Cl ^- ), polyoxyethylene (--OCH ₂ CH ₂ O ^- ), glycolic acid ethoxylate But are not limited to, copolymers of styrene-acrylonitrile and styrene-acrylonitrile.

The rutile titanium dioxide nano-disperse sol according to the present invention is produced by the above-described production method of the present invention, and the titanium dioxide particle has a rutile crystal phase, and can have a single crystal size of 8 to 12 nm and an average particle diameter of 15 to 70 nm If it is out of the above range, a dispersion sol having high transparency can not be obtained, which is not preferable.

Since the titanium dioxide particles have monodispersity with narrow particle distribution, even if the titanium dioxide particles having the size of the single crystal and the average particle size are dispersed in the alcohol, the aggregation of the particles does not occur and the stable sol form can be maintained have.

The titanium dioxide nanodispersion sol may have a solid content of 10 to 50% by weight of titanium dioxide, and may be dispersed at a high concentration.

Examples and Comparative Examples

Property measurement

1) Measurement of crystal size and size of single crystals (D _hkl )

Titanium dioxide particles were measured for XRD using a C5000 product from Siemens, and the size of the single crystal was calculated using the Scherrer's equation (Equation 1).

[Equation 1]

Where K is 0.9, [lambda] is 0.15418 nm, [beta] is FWHM and [theta] is the peak position of FWHM.

2) Average particle diameter (D ₅₀ )

The particle diameters of the titanium dioxide particles were measured by photon correlation or dynamic light scattering (PCS-Photon Correlation Spectroscopy or DLS-Dynamic Light Scattering) using ELSZ-1000 manufactured by Otsuka. Samples were measured on an ethanol base and the median particle size (D ₅₀ ) was used.

Example  One

In a 500 ml flask, 50 g of titanium (IV) tetraisopropoxide was added to 200 ml of an aqueous solution of HNO ₃ , followed by stirring. The mixed solution was heated at 80 DEG C, and then stirred at 500 to 600 rpm for 24 hours to obtain a rutile-based titanium dioxide precipitate. The rutile titanium dioxide precipitate was washed with distilled water and ethanol using centrifugation until the ionic conductivity of the rutile titanium dioxide precipitate was at least 3 mu S / cm or less. Next, the washed rutile titanium dioxide was diluted to 2 wt% in the ethanol base. In a 250 ml vessel, 200 g of the diluted rutile based titanium dioxide sol was milled with zirconia beads having a bead size of 0.3 mm or less at 2000 to 3000 rpm for 1 hour. After the milling, the obtained sol dispersed with rutile titanium dioxide was analyzed by XRD (particle size analyzer), PSA (micro particle size analyzer) and TEM (transmission electron microscope). The crystal structure, the size and average particle size (D ₅₀ ) The results are shown in Table 1 and Fig. 2, Fig. 3 and Fig.

Example  2

(IV) oxychloride (TiOCl ₂ ) -hydrochloric acid aqueous solution of 40% concentration was added to 200 ml of ethanol solvent and stirred. Then, the mixture was placed in a 500 ml flask, and the aqueous solution was heated at 40 ° C and then heated at 500 to 600 rpm for 48 hours And then the solution was agitated and dissolved to obtain a rutile titanium dioxide precipitate. The rutile titanium dioxide dispersed sol was prepared in the same manner as in Example 1, and the dispersed sol thus obtained was analyzed by XRD. The crystal structure, the size of the single crystal and the average particle diameter (D ₅₀ ) were measured. The results are shown in Table 1 below.

Example  3

67 g of a 40% strength titanium (IV) oxychloride-hydrochloric acid aqueous solution was added to 200 ml of distilled water and stirred. Then, the solution was placed in a 500 ml flask, and the aqueous solution was heated at 80 ° C and then dissolved by stirring at 500 to 600 rpm for 24 hours , A rutile-based titanium dioxide dispersed sol was prepared in the same manner as in Example 1, except that the rutile-based titanium dioxide precipitate was obtained through an aging process. The dispersed sol thus obtained was analyzed by XRD and the crystal structure, single crystal Size and average particle diameter (D ₅₀ ) were measured. The results are shown in Table 1 below.

Example  4

67 g of a 40% strength titanium (IV) oxychloride-hydrochloric acid aqueous solution was added to 200 ml of distilled water, and the mixture was stirred in a 500 ml flask. The aqueous solution was heated at 25 ° C. and stirred at 500 to 600 rpm for 72 hours , A rutile-based titanium dioxide dispersed sol was prepared in the same manner as in Example 1, except that the rutile-based titanium dioxide precipitate was obtained through an aging process. The dispersed sol thus obtained was analyzed by XRD and the crystal structure, single crystal Size and average particle diameter (D ₅₀ ) were measured. The results are shown in Table 1 below.

Example  5

A rutile-type titanium dioxide dispersed sol was prepared in the same manner as in Example 1 except that an aqueous solution of propionic acid was used instead of the aqueous solution of HNO _{3. The} dispersion sol thus obtained was analyzed by XRD and the crystal structure, The particle diameter (D ₅₀ ) was measured and the results are shown in Table 1 below.

Example  6

A rutile-type titanium dioxide dispersed sol was prepared in the same manner as in Example 1 except that 1 g of a polyethylene oxide (PEO) polymer was further added during stirring for the preparation of the mixed solution in Example 1 to obtain a mixed solution, The crystal structure, the size and the average particle diameter (D ₅₀ ) of the single crystal were measured, and the results are shown in Table 1 below.

Example  7

A rutile titanium dioxide dispersed sol was prepared in the same manner as in Example 1, except that 10% by weight of the acrylate copolymer was added to the titanium dioxide solid content as the additive at the milling in Example 1, The obtained dispersion sol was analyzed by XRD, and the crystal structure, the size and the average particle diameter (D ₅₀ ) of the single crystal were measured, and the results are shown in Table 1 below.

Comparative Example  One

To 100 ml of distilled water, 0.1 mol of 98% titanium tetraisopropoxide and 1M of HNO ₃ were mixed, and the mixture was stirred in a 500 ml flask. The mixed solution was heated at 65 ° C., stirred at 500 to 600 rpm for 2 hours, and subjected to hydrothermal treatment at 180 ° C. for 24 hours to obtain an anatase-type titanium dioxide precipitate. The powder thus obtained was analyzed by XRD, , The size of the single crystal and the average particle size (D ₅₀ ) were measured. The results are shown in Table 1 below.

Comparative Example  2

A titanium dioxide precipitate was prepared in the same manner as in Example 3, except that the dissolution and aging process was carried out for 12 hours in Example 3. The resulting precipitate was washed with distilled water and ethanol until the ionic conductivity became at least 3 mu S / cm or less &Lt; / RTI &gt; and dried to obtain a powder. The powder thus obtained was obtained by anatase and rutile titanium dioxide structures and analyzed by XRD. The crystal structure, the size and the average particle size (D ₅₀ ) of the single crystal were measured, and the results are shown in Table 1 below.

Comparative Example  3

A titanium dioxide precipitate was prepared in the same manner as in Example 3, except that the aqueous solution was heated at 80 ° C in Example 3, stirred at 500 to 600 rpm for 5 hours, and then subjected to hydrothermal treatment for 12 hours. The precipitate was washed with distilled water and ethanol using centrifugation until the ionic conductivity was at least 3 μS / cm and dried to obtain a powder. The powder thus obtained was obtained with an anatase type titanium dioxide structure and analyzed by XRD. The crystal structure, the size and the average particle diameter (D ₅₀ ) of the single crystal were measured, and the results are shown in Table 1 below.

Comparative Example  4

Rutile titanium dioxide powder (Du Pont) having a particle size shown in the following Table 1 was bead-milled under the same conditions as in Example 1 in an ethanol solvent to prepare a rutile-type titanium dioxide dispersed sol. The rutile titanium dioxide dispersed sol was analyzed by XRD, The size and average particle size (D ₅₀ ) of the single crystal were measured, and the results are shown in Table 1 and FIG.

Crystalline phase Size of single crystal (nm) Average particle diameter (D ₅₀ ) (nm) Example


One Ruta day 12 35 2 Ruta day 11.3 65 3 Ruta day 11.7 20 4 Ruta day 9.5 37 5 Ruta day 9.9 36 6 Ruta day 11.7 35 7 Ruta day 11.7 20 Comparative Example

One Anatase 7.7 - 2 Anatase / ruta day 13.6 - 3 Anatase 12.0 - 4 Ruta day 23.8 194

As can be seen from the above Table 1, the titanium oxide particles of the rutile-type titanium oxide dispersed sol prepared in Examples 1 to 7 had a larger crystal size and a larger average particle diameter than the titanium dioxide powder prepared in Comparative Examples 1 to 4 D ₅₀ ) was measured to be small and it was found that the dispersion was excellent.

The titanium dioxide particles of the dispersed sol prepared in Comparative Example 1 were obtained as anatase crystal phase using a precursor of titanium tetraisopropoxide.

The titanium dioxide particle of the dispersion sol prepared in Comparative Example 2 was obtained as an anatase / rutile composite crystal. The size of the single crystal was 13.6 nm, which was 2 to 3 nm larger than the single crystal size of the titanium dioxide particles according to Examples.

The titanium dioxide particles of the dispersed sol prepared in Comparative Example 3 were larger in size than the single crystals produced in the examples and were obtained as atanas crystal phase through reaction time and hydrothermal treatment.

In Comparative Example 4, milling was performed using a commercial powder having an average particle size of 194 nm. As a result, a dispersion sol having a size of a single crystal larger than that of Example 1 was obtained.

Further, as shown in Fig. 4, in the case of Example 1, a highly transparent titanium dioxide dispersed sol was obtained, whereas in Comparative Example 4, an opaque titanium dioxide dispersed sol was obtained.

Claims (14)

Preparation of rutile-based titanium dioxide nanodispersed sol, comprising the steps of:
Way:
1) adding a titanium precursor to water or alcohol in the presence of an acid,
Deg.] C for 70 to 80 hours or hydrothermal reaction at 40 to 80 [deg.] C for 20 to 50 hours to obtain a titanium dioxide mixed solution;
2) The above titanium dioxide mixed solution was diluted with alcohol and then milled to prepare dispersed sol
&Lt; / RTI &gt;
The method according to claim 1,
Wherein the titanium precursor is at least one selected from the group consisting of titanium tetraisopropoxide (TTIP) and titanyl chloride (TiOCl ₂ ) in the step ₁ ).
The method according to claim 1,
Wherein the acid in the step 1) is at least one selected from the group consisting of nitric acid, sulfuric acid, hydrochloric acid and acetic acid. The method according to claim 1,
Wherein the alcohol used in step (1) is at least one selected from the group consisting of methanol, ethanol, propanol, isopropyl alcohol, butyl alcohol and isobutyl alcohol.
delete delete The method according to claim 1,
Wherein the water-soluble polymer is further added in the step 1). 8. The method of claim 7,
Wherein the water-soluble polymer is at least one selected from non-ionic, anionic, and cationic water-soluble polymers.
The method according to claim 1,
Wherein the alcohol used in the step 2) is at least one selected from the group consisting of methanol, ethanol, propanol, isopropyl alcohol, butyl alcohol and isobutyl alcohol.
The method according to claim 1,
Wherein the bead mill is used for the milling in the step 2), and the zirconia bead size of the bead mill is 0.3 mm or less.
The method according to claim 1,
A method for producing a rutile-type titanium dioxide nano-disperse sol comprising the steps of: 12. The method of claim 11,
The dispersant may be selected from the group consisting of carboxylic acid salts (RCOO ^- M ⁺ ), sulfonic acid salts (RSO ₃ ^- M ⁺ ), sulfuric acid ester salts (ROSO ₃ ^- M ⁺ ), phosphoric acid ester salts (RPO ₃ ^- Na ^{2 +} ), ammonium halides R4N ⁺ Cl ^-), polyoxyethylene ^{_{(-OCH 2 CH 2 O -)}} , Tra-ray lauryl ether ethoxylate glycolic acid and styrene copolymer of acrylonitrile rutile titanium dioxide ilgye method for producing a nano-dispersion sol.
A titanium dioxide particle produced by the manufacturing method according to any one of claims 1 to 4 or 12 to 12, wherein the titanium dioxide particle has a rutile crystal phase, the size of the single crystal is from 8 to 12 nm, Rutile-based titanium dioxide nano-disperse sol having an average particle diameter of 15 to 70 nm.
14. The method of claim 13,
Wherein the titanium dioxide nano-disperse sol is a rutile-type titanium dioxide nano-disperse sol having a solid content of titanium dioxide of 1 to 50 wt%.

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