KR20040073665A - Method for preparing nano-size anatase titania powder and sol by glycol process - Google Patents

Abstract

PURPOSE: Provided are a method for preparing a nanosized anatase titania having high crystallinity by simultaneous precipitation, by adding a starting material of titanium to glycol, and a method for preparing high concentration sol solution of titania having excellent dispersibility by using the nanosized anatase titania in aqueous or alcoholic solution, without special treatment. CONSTITUTION: The method for preparing powder and sol of nanosized anatase titania by using glycol process, is characterized by comprising the steps of (i) adding a starting material of titanium to glycol which is a solvent, (ii) heating the glycol solution comprising the titanium to 50-250 deg.C to obtain a precipitate, (iii) filtrating or centrifuging and washing the precipitate, and (iv) forming a sol solution of nanosized anatase titania by using the precipitate.

Description

Method for preparing nano-size anatase titanium dioxide powder and sol using glycol process {Method for preparing nano-size anatase titania powder and sol by glycol process}

The present invention relates to a nano-size anatase-type titanium dioxide powder using a glycol process and a method for producing nanosol having excellent dispersibility. More particularly, the present invention relates to sterilizing pathogens using light energy or in the air or New and more economical method for producing anatase type titanium dioxide powder which does not require high temperature firing or hydrothermal reaction process when producing nano sized anatase type titanium dioxide powder having excellent photocatalytic properties as a photocatalyst used to decompose organic pollutants in water and It relates to a nano-sol manufacturing method made of the powder.

In general, the photocatalyst material is a material that photooxidizes and removes organic pollutants in the air or water adsorbed to the photocatalyst layer by free radical reaction. The characteristics of the photocatalyst material depend on the semiconductor metal oxide used as the photocatalyst layer, and titanium dioxide is the most easily used and stable photocatalyst among the photocatalysts studied to date. In order for titanium dioxide to function as a photocatalyst, it must have an anatase type crystallinity. Anatase-type titanium dioxide has a band gap energy (Eg) of about 3.2 eV, and when it receives a larger energy (for example, ultraviolet rays), the outermost electrons are easily excited and transfer to the conduction band, and a hole is formed in the valence band to form a photocatalyst layer. Go to the surface. When the holes and the water or OH- on the surface react, OH radicals with strong oxidizing power are produced. It is known. It is recognized that such titanium dioxide powder has excellent properties as the particles are fine and the specific surface area is wide.

As a method for producing titanium dioxide powder, sulfuric acid method, chlorine method, metal alkoxide method and the like are known.

Sulfuric acid is a method of producing titanium dioxide by dissolving an ilmenite ore, a titanium-containing mineral, in sulfuric acid, followed by purification, hydrolysis, and calcining. Chlorine is a method of using titanium tetrachloride (TiCl4). It is a method for producing titanium dioxide by oxidative decomposition through liquid or gas phase reaction.

Since the sulfuric acid method and the chlorine method are excellent in economic efficiency, they are currently the most widely used methods and are used for the production of titanium dioxide powders used as raw materials for pigments and cosmetics. However, the titanium dioxide powders produced by the sulfuric acid method and the chlorine method have strong specific aggregates during the heat treatment process by calcination even if their particle size is relatively large (about 100 to 1000 nm) or the particle size is small. It is known that the characteristics of the photocatalyst, which are greatly affected by particle size and specific surface area, are not excellent because they are significantly reduced.

Accordingly, in order to produce titanium dioxide powder having finer particle size and well controlled agglomeration state, titanium dioxide, such as particle shape and particle size distribution, has been formed by sol-gel method or hydrothermal synthesis method. Research to control the characteristics of the raw material powder is actively being conducted. In order to prepare spherical titanium dioxide powder having a uniform size, a method using a metal alkoxide is mainly used. This sol-gel method forms a powder having a fine spherical uniform size of 1.0 μm or less, but starting materials Phosphorus alkoxide itself causes violent hydrolysis reactions in the air, so the reaction conditions must be strictly controlled. Since alkoxide is expensive, it is currently not commercialized and is progressing to a laboratory scale. And the hydrothermal synthesis method has a good state of the powder obtained, but the disadvantage is that the continuous process is impossible because the reaction vessel (autoclave) mainly maintained at high temperature, high pressure conditions.

Therefore, the present invention was invented to solve the above problems, in the preparation of nano-size anatase-type titanium dioxide powder and nano sol, by using a glycol process, inexpensive raw materials such as sulfuric acid method or chlorine method A process for producing nano-size anatase-type titanium dioxide which does not require additional treatment even though the process is simple and does not require additional treatment, and high concentration of dioxide is easy to introduce various additives using the nano-size anatase-type titanium dioxide prepared by the above method. Provided is a method for preparing a titanium sol solution.

1 is an X-ray diffraction graph of nano-sized anatase type titanium dioxide powder prepared by glycol process at 100 ° C.

Figure 2 is a graph showing the particle size distribution of the nano-size anatase type titanium dioxide powder prepared by the glycol process at 100 ℃.

Figure 3 is an X-ray diffraction graph of the nano-size anatase type titanium dioxide powder prepared by the glycol process at 150 ℃.

Figure 4 is a graph showing the particle size distribution of the nano-size anatase type titanium dioxide powder prepared by the glycol process at 150 ℃.

Figure 5 is a transmission electron microscope photograph of the nano-size anatase type titanium dioxide powder prepared by the glycol process at 150 ℃.

6 is an X-ray diffraction graph of nano-sized anatase type titanium dioxide powder prepared by glycol process at 200 ° C.

Figure 7 is a graph showing the particle size distribution of the nano-size anatase type titanium dioxide powder prepared by the glycol process at 200 ℃.

Figure 8 is a transmission electron microscope photograph of the nano-size anatase type titanium dioxide powder prepared by the glycol process at 200 ℃.

Figure 9 is a transmission electron micrograph of the nano-size anatase type titanium dioxide powder prepared by the glycol process at 150 ℃ when the concentration of the titanium starting material is 0.75M.

10 is a transmission electron micrograph of a nano-size anatase-type titanium dioxide powder prepared by the glycol process at 150 ℃ when the concentration of the titanium starting material is 1M.

11 is a transmission electron micrograph of a nano-sized anatase type titanium dioxide powder prepared by the glycol process at 150 ℃ when the concentration of the titanium starting material is 2M.

Figure 12 is a graph showing the average particle size of the nano-size anatase type titanium dioxide powder prepared by the glycol process by changing the concentration of the titanium starting material at 150 ℃.

Figure 13 is a graph showing the particle size distribution of a 20wt% sol aqueous solution made of nano-size anatase type titanium dioxide powder prepared by the glycol process according to the present invention.

Figure 14 is a graph showing the particle size distribution of a 10wt% sol aqueous solution prepared by washing the nano-size anatase-type titanium dioxide powder prepared by the glycol process according to the present invention until the neutral state.

Figure 15 is a graph showing the particle size distribution of the 10wt% sol methanol solution made of nano-size anatase type titanium dioxide powder prepared by the glycol process according to the present invention.

The present invention relates to a method for preparing nano-sized anatase type titanium dioxide powder and a nano sol using a glycol process under atmospheric pressure, wherein titanium starting material is added to glycol, and the crystallinity is high by spontaneous precipitation reaction. The present invention relates to a method for producing anatase-type titanium dioxide having a large size, and to a method for producing a high concentration of titanium dioxide sol solution having excellent dispersibility in an aqueous solution or an alcohol solution using a nano-size anatase-type titanium dioxide prepared by the above method.

Hereinafter, the present invention will be described in detail.

Referring to the step of manufacturing a nano-size anatase type titanium dioxide according to the present invention,

Adding a titanium starting material to a glycol as a solvent;

A second step of obtaining a precipitate by maintaining the temperature of the glycol solution to which the titanium starting material is added in a temperature range of 50 to 25 ° C .;

A third step of filtering or centrifuging and washing the precipitate;

A fourth step of forming a nano-size anatase type titanium dioxide sol solution using the precipitate;

Is made of.

In detail for each step described above,

In the first step of adding a titanium starting material to the glycol, the solvent may be continuously stirred when the starting material is added or when the glycol solution containing the titanium starting material is kept at elevated temperature to cause a spontaneous precipitation reaction.

Type of glycol used in the above step is ethylene glycol (ethyleneglycol), 1,2-butanediol (1,2-butanediol), 1,3-butanediol (1,3-butanediol), 1,4-butanediol (1, 4-butanediol), 2,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,4-pentanediol, 1,4-pentanediol, 1,5- Pentanediol (1,5-pentanediol), 2,4-pentanediol (2,4-pentanediol), 1,2-hexanediol (1,2-Hexanediol), 1,5-hexanediol (1,2-Hexanediol ), 1,6-hexanediol (1,6-Hexanediol) and 2,5-hexanediol (2,5-Hexanediol) may be used.

In addition, the titanium starting material is not particularly limited, in particular, titanium tetrachloride (TiCl 4), titanium hypochlorite (TiOCl 2), titanium sulfate (TiOSO 4), titanium ethoxide (Ti (OC 2 H 5) 4), and titanium isopropoxide (Ti (OCH (CH3) 2) 4), titanium nitrate (Ti (NO3) 4), titanium propoxide (Ti (OCH2CH2CH3) 4) and the like are preferably used.

Titanium tetrachloride used in the embodiment of the present invention has a high vapor pressure at room temperature and generates severe hydrochloric acid gas by reacting with moisture in the air, thus making it difficult to quantitatively quantitatively inhibit the quantitative precipitation reaction and the reaction with moisture in the air. In order to dilute the unstable titanium tetrachloride solution, a stable aqueous solution having a constant titanium ion concentration may be used. In addition, titanium alkoxide also causes a vigorous hydrolysis reaction in air, so it can be used after dilution with stable solution using isopropanol.

When glycol is used as a solvent, it is stable regardless of the concentration of titanium starting material. Therefore, it is not necessary to adjust the concentration of titanium starting material to control the hydrolysis rate as in the case of using an aqueous solution as a solvent. In addition, by adjusting the concentration of the titanium starting material, the average particle size of the titanium dioxide sol solution of the final product can be adjusted from 10nm to 200nm. The above concentration means the concentration of titanium starting material with respect to water as a solvent.

In the second step of the present invention, the precipitation solution is performed while maintaining the glycol solution to which a predetermined amount of the titanium starting material is added at a constant temperature (50 ° C. to 250 ° C.). Precipitation takes some time to occur, which is the time required to evaporate the aqueous solution or isopropanol added with the titanium starting material in the glycol solution, and also means that there is an activation barrier to reach supersaturation for the precipitation to occur. . After evaporation of the added aqueous solution or isopropanol and maintained at the precipitation temperature for 2 hours or more, the supersaturated state is reached and the white weakly aggregated nano-size anatase titanium dioxide powder is precipitated while crossing the activation barrier.

The reaction temperature in the precipitation step may be carried out at 25 ~ 250 ℃. More preferably, the reaction temperature in the precipitation step is 100 ~ 200 ℃. In order to control the evaporation and reaction time of the aqueous solution or isopropanol added with the titanium starting material in the glycol solution to about 2 hours, the precipitation reaction is preferably performed at 100 ° C. or higher, and when the temperature occurs at 200 ° C. or higher, titanium dioxide It is difficult to control the precipitation rate of the powder, and the aggregation of the formed titanium dioxide powder becomes severe, making dispersion difficult.

During the precipitation reaction, the stirring speed does not need to adjust the stirring speed until precipitation occurs, but when precipitation starts to occur, the stirring speed is preferably adjusted to 50 rpm or less. If the stirring speed is 50rpm or more, the aggregation of the titanium dioxide powder formed during precipitation becomes severe and the dispersion becomes difficult.

In addition, in the present invention, by controlling the agglomeration of the titanium dioxide precipitate by appropriately changing the reaction temperature and the stirring speed, the average particle size of the titanium dioxide sol solution of the final product can be adjusted from 10nm to 200nm.

The average particle size according to the reaction temperature is described in detail in Examples 1 to 4 described below.

The reaction time in the precipitation step may increase as the amount of titanium starting material increases. Although there is no significant correlation between the reaction time and the crystallization rate of anatase type titanium dioxide, it is necessary to give a relatively long precipitation time when the amount of titanium starting material is large. Generally, a reaction time of about 2 to 10 hours is given.

The titanium dioxide precipitate prepared in the second step of the present invention is subjected to a post-treatment process of filtration, washing or centrifugation in the third step to finally prepare a nano-size anatase titanium dioxide sol solution using the precipitate. In the filtration and washing processes of the post-treatment process, if the precipitate is agglomerated severely depending on the degree of aggregation of the crystalline titanium dioxide precipitate, the filter is filtered using a filter paper having a porosity of 0.1 μm or more, or the agglomeration of the precipitate is not severe After removing the glycol solution using a centrifuge, it is washed with a specially adjusted buffer solution or ethanol for complete washing of the precipitate and prevention of peptizing. If the water is used without any special treatment for cleaning, the formed chip body can be peptized so that it cannot pass through all of the 0.1 μm pore filter paper or can not be separated by winsim.

In the fourth step of the present invention, the washed precipitate is peptized in water to prepare a nano-size anatase type titanium dioxide sol solution, which is finally commercialized. The cleaned titanium dioxide precipitate is naturally peptized in water, so no special equipment or dispersant is required, but it can also be sonicated to reduce the time it is peptized. The sol solution may be prepared using alcohol, glycol, or another organic solvent. In this case, the anatase type titanium dioxide sol solution is prepared using a wet dispersion apparatus for sonication or nanoparticle dispersion.

Hereinafter, a method for preparing a nano sol of the present invention will be described in detail with reference to Examples.

However, the following examples are examples for preparing the nano-sol of the present invention, and the claims of the present invention are not reduced or limited by the following examples.

Examples 1 to 3 are examples of a method for producing anatase-type titanium nano sol by varying the reaction temperature, Example 4 was prepared by mixing the additive in the nano-sol prepared in Example 2 to prepare anatase-type titanium dioxide + SiO 2 Nazo sol Examples 5 to 8 are examples of a method for preparing an anatase titanium dioxide sol solution by varying the concentration of titanium tetrachloride.

Example 1 Preparation of Anatase Type Titanium Dioxide Nanosol

The titanium tetrachloride stock solution was slowly added to 1,4-butanediol so as to have a titanium ion concentration of 0.5 M (mol) and avoided contact with air in the hood, followed by stirring for 12 hours while raising the temperature to 100 ° C. Stirring speed was below 50rpm so as not to precipitate the precipitate. The titanium dioxide precipitate thus obtained was removed using a centrifuge to remove 1,4-butanediol solution and washed with ethanol. The washed precipitate was peptized in water to prepare a 10 wt% nano sized anatase type titanium dioxide sol solution.

1 is a graph confirming the crystal peak of the anatase-type titanium dioxide as a result of the crystal coating after forming a film by coating the sol solution prepared above on a glass plate, the horizontal axis in the graph means the scattering angle, Means relative quantity.

Figure 2 is a graph of the average particle size of the prepared sol was analyzed by a particle size analyzer it can be seen that the size of the titanium dioxide powder is uniformly dispersed from 6nm to 25nm, the average size is about 9nm Able to know.

Example 2 Preparation of Anatase Type Titanium Dioxide Nanosol

The titanium tetrachloride stock solution was slowly added to 1,4-butanediol so as to have a titanium ion concentration of 0.5 M, avoiding contact with air in the hood, followed by stirring for 6 hours while raising the temperature to 150 ° C. Stirring speed was below 50rpm so as not to precipitate the precipitate. The titanium dioxide precipitate thus obtained was removed using a centrifuge to remove 1,4-butanediol solution and washed with ethanol. The washed precipitate was peptized in water to prepare a 10 wt% nano sized anatase type titanium dioxide sol solution.

3 is a graph confirming the crystal peak of the anatase type titanium dioxide after the sol solution prepared from the above method by dip coating the glass plate to form a film and the crystallinity was examined, Figure 4 is the average particle size of the prepared sol It can be seen that the size of the titanium dioxide analyzed from the particle size analyzer is uniformly distributed in the size of 7nm to 11nm and the average size is 8.6nm.

FIG. 5 is a photograph of the nano-sized anatase-type titanium dioxide powder prepared above using a transmission electron microscope, and it can be seen that the primary particles of about 5 nm are well dispersed in the titanium dioxide powder.

Example 3 Preparation of Anatase Type Titanium Dioxide Nanosol

The titanium tetrachloride stock solution was slowly added to 1,4-butanediol so as to have a titanium ion concentration of 0.5 M, avoiding contact with air in the hood, followed by stirring for 3 hours while raising the temperature to 200 ° C. Stirring speed was below 50rpm so as not to precipitate the precipitate. The titanium dioxide precipitate obtained above was removed with a 1,4-butanediol solution using a centrifuge and washed with ethanol. The washed precipitate was peptized in water to prepare a 10 wt% nano sized anatase type titanium dioxide sol solution.

6 is a graph confirming the crystal peak of the anatase type titanium dioxide as a result of the crystallization of the sol solution prepared by the above method to form a film by dip coating on a glass plate, Figure 7 is the average particle size of the sol prepared above Is a graph analyzed from the particle size analyzer, it can be seen that the size of titanium dioxide is distributed from 10nm to 100nm, the average size is about 18nm. In addition, it can be seen from the graph of FIG. 7 that a small amount of aggregates of 100 nm or more are formed.

FIG. 8 is a photograph of the nano-sized anatase-type titanium dioxide powder prepared above using a transmission electron microscope, and it can be seen that primary particles of about 5 nm are aggregated and dispersed at 10-20 nm. .

Example 4 Preparation of Anatase Type Titanium Dioxide + SiO 2 Nanosol

The titanium tetrachloride stock solution was slowly added to the 1,4-butanediol titanium ion concentration to 0.5M to avoid contact with air in the hood, followed by stirring. Stirring speed was below 50rpm so as not to precipitate the precipitate. The titanium dioxide precipitate thus obtained was removed using a centrifuge to remove 1,4-butanediol solution and washed with ethanol. The washed precipitate was peptized in water to prepare a nano-size anatase type titanium dioxide sol solution. Anatase type titanium dioxide + SiO 2 nanosol was prepared by slowly adding a mixed solution of tetraethyl oxosilicate to the titanium dioxide sol solution prepared from the above method so that the silicon concentration was 0.5M.

The sol solution prepared from the above method was dip-coated on a glass plate to form a film, and then the crystal peaks of the anatase-type titanium dioxide were confirmed. The particle size in the sol prepared above was confirmed that the primary particles of about 5nm from the transmission electron microscope aggregated to 10 ~ 20nm well dispersed.

Example 1 to Example 4 shown above using Table 1 are as follows.

TABLE 1

Example 1 Example 2 Example 3 Example 4 Starting material Titanium tetrachloride Titanium tetrachloride Titanium tetrachloride Titanium tetrachloride menstruum 1,4-butanediol 1,4-butanediol 1,4-butanediol 1,4-butanediol Reaction temperature 100 ℃ 150 ℃ 200 ℃ 150 ℃ Stirring speed 50 rpm 50 rpm 50 rpm 50 rpm additive - - - Tetraethylolsosilicate Particle size 9 nm 5 nm 18 nm 5 nm

As can be seen in Table 1, the reaction temperature is 9 nm, the size of the titanium dioxide produced while raising the temperature to 100 ~ 150 ℃, it can be seen that the manufacturing method according to Example 2.

Example 5 Preparation of Anatase Type Titanium Dioxide Nanosol

The titanium tetrachloride stock solution was slowly added to 1,4-butanediol so as to have a titanium ion concentration of 0.75 M, while avoiding contact with air in the hood, followed by stirring for 6 hours while raising the temperature to 150 ° C. Stirring speed was below 50rpm so as not to precipitate the precipitate. The titanium dioxide precipitate thus obtained was removed using a centrifuge to remove 1,4-butanediol solution and washed with ethanol. The washed precipitate was peptized in water to prepare a nano-size anatase type titanium dioxide sol solution. 9 is a transmission electron micrograph of the anatase type titanium dioxide powder prepared by the above method, and it can be seen that the average particle size is about 9.2 nm.

Example 6 Preparation of Anatase Type Titanium Dioxide Nanosol

The titanium tetrachloride stock solution was slowly added to 1,4-butanediol so as to have a titanium ion concentration of 1.0 M, while avoiding contact with air in the hood, followed by stirring for 6 hours while raising the temperature to 150 ° C. Stirring speed was below 50rpm so as not to precipitate the precipitate. The titanium dioxide precipitate thus obtained was removed using a centrifuge to remove 1,4-butanediol solution and washed with ethanol. The washed precipitate was peptized in water to prepare a nano-size anatase type titanium dioxide sol solution.

10 is a transmission electron micrograph of the anatase-type titanium dioxide powder prepared by the above method, it can be seen that the average particle size is about 24nm.

Example 7 Preparation of Anatase Type Titanium Dioxide Nanosol

The titanium tetrachloride stock solution was slowly added to 1,4-butanediol so as to have a titanium ion concentration of 1.5 M, avoiding contact with air in the hood, followed by stirring for 6 hours while raising the temperature to 150 ° C. Stirring speed was below 50rpm so as not to precipitate the precipitate. The titanium dioxide precipitate thus obtained was removed using a centrifuge to remove 1,4-butanediol solution and washed with ethanol. The washed precipitate was peptized in water to prepare a nano-size anatase type titanium dioxide sol solution.

Transmission electron micrographs of the anatase-type titanium dioxide powder prepared by the above method showed that the average particle size was about 27 nm.

Example 8 Preparation of Anatase Type Titanium Dioxide Nanosol

The titanium tetrachloride stock solution was slowly added to 1,4-butanediol so as to have a titanium ion concentration of 2.0 M, avoiding contact with air in the hood, followed by stirring for 6 hours while raising the temperature to 150 ° C. Stirring speed was below 50rpm so as not to precipitate the precipitate. The titanium dioxide precipitate thus obtained was removed using a centrifuge to remove 1,4-butanediol solution and washed with ethanol. The washed precipitate was peptized in water to prepare a nano-size anatase type titanium dioxide sol solution.

11 is a transmission electron micrograph of the titanium dioxide powder prepared by the above method, it can be seen that the average particle size is about 33nm.

Example 5 to Example 8 are shown in Table 2 below.

TABLE 2

Example 5 Example 6 Example 7 Example 8 Starting material Titanium Tetrachloride Titanium Tetrachloride Titanium Tetrachloride Titanium Tetrachloride menstruum 1,4-butanediol 1,4-butanediol 1,4-butanediol 1,4-butanediol Concentration of titanium tetrachloride 0.75M 1.0M 1.5M 2.0M Stirring speed 50 rpm 50 rpm 50 rpm 50 rpm Particle size 9.2 nm 24 nm 27 nm 33 nm

As can be seen in Table 1 and 2 above, the reaction temperature is suitable for 150 ℃, the stirring speed is 50rpm. The concentration of the starting material is 0.75M or less in the embodiment it can be seen that the size of the titanium dioxide is formed small, the particle size distribution can be seen that evenly distributed.

12 is a graph of Table 2 above.

FIG. 13 shows a particle size distribution of the aqueous titanium dioxide powder prepared by the glycol process according to Example 2 of the aqueous solution by using a 20 wt% sol solution, and the particle size is uniformly distributed between 8 nm and 13 nm. It can be seen that the average particle size is 10.5nm.

14 is a titanium dioxide prepared by the glycol process of the present invention is acidic, 10wt% sol aqueous solution prepared by washing the acidic titanium dioxide powder with a buffer solution (pH 7, acetic acid solution) until neutral state In the graph showing the particle size distribution of, it can be seen that the particle size is uniformly distributed in the range of 8 nm to 20 nm, and almost no aggregation occurs, and the average size is 12 nm.

15 is a graph showing the particle size distribution of the titanium dioxide powder prepared by the glycol process of the present invention to prepare a 10wt% methanol solution, it can be seen that the size of the particles are uniformly distributed to 15nm ~ 50nm, average It can be seen that the size of the particles is 25 nm.

13 to 15, the particle size distribution of the sol solution prepared by using another titanium dioxide powder of the present invention or an aqueous solution prepared by the neutral solution shows a uniform distribution similar to the particle size distribution in the powder state. It can be seen that little aggregation occurs.

The present invention relates to a nano-size anatase-type titanium dioxide powder using a new glycol process and a method for preparing a nano sol having excellent dispersibility. Since the glycol is used as a solvent, it is easy to be thermodynamically formed in an aqueous solution. Nano sized anatase type titanium dioxide powder with excellent photocatalytic properties can be prepared while preventing the precipitation of titanium.Since precipitation of titanium dioxide crystals directly from glycol by spontaneous precipitation reaction, long-term aging or high temperature firing or hydrothermal reaction process is required. A new and more economical method for producing anatase titanium dioxide powder and a nano sol made of the powder can be prepared. In addition, since spontaneous dispersion occurs in the aqueous solution without using a dispersant, the nano-size anatase-type titanium dioxide aqueous solution formed when the titanium dioxide is manufactured by the method of the present invention has excellent dispersion stability for a long time and can be used as a coating solution without any other treatment. Can be. Because of excellent dispersion stability due to spontaneous dispersion, in preparing a titanium dioxide photocatalyst having various properties added with various additives, it is possible to reduce the possibility of various problems such as reaction, precipitation, and phase separation by additives.

Claims (9)

In the nano-size anatase-type titanium dioxide powder and nano-sol manufacturing method using a glycol process, Adding a titanium starting material to a glycol as a solvent; A second step of obtaining a precipitate by maintaining the temperature of the glycol solution added with the titanium starting material in a temperature range of 50 ° C to 250 ° C; A third step of filtering or centrifuging and washing the precipitate; A fourth step of forming a nano-size anatase type titanium dioxide sol solution using the precipitate; Nano-size anatase type titanium dioxide powder and sol production method using a glycol process, characterized in that consisting of. The method of claim 1, In the step of adding a titanium starting material to the glycol of step 1, the kind of glycol used as the solvent is ethylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3- Butanediol, 1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 1,5-hexanediol, 1,6-hexanediol And 2,5-hexanediol nano-size anatase type titanium dioxide powder and a sol manufacturing method using a glycol process, characterized in that selected from the group consisting of. The method of claim 1, In the step of adding a titanium starting material to the glycol of step 1, the titanium starting material is titanium tetrachloride, titanium hypochlorite, titanium sulfate or titanium alkoxide, characterized in that the nano-size anatase type titanium dioxide powder using a glycol process And sol preparation methods. The method of claim 1, In the step of obtaining a precipitate by heating the glycol solution to which the titanium starting material of step 2 is added in a temperature range of 50 ℃ to 250 ℃, More specifically, a method for producing nano-size anatase type titanium dioxide powder and sol using a glycol process, characterized in that the glycol solution is heated to 100 ° C. to 150 ° C. to obtain a precipitate. The method of claim 1, Nano-size anatase-type titanium dioxide powder, characterized in that the average particle size of the anatase-type titanium dioxide photocatalyst increases as the concentration of the titanium starting material increases when the precipitation reaction occurs while raising the glycol solution to which the titanium starting material is added. And sol preparation methods. The method of claim 5, Titanium starting material concentration is 0.4 ~ 0.8M nano-size anatase type titanium dioxide powder and sol production method characterized in that. The method of claim 1, In the step of forming a nano-size anatase type titanium dioxide sol solution using the precipitate of step 4, a dispersant is used to shorten the peptizing time. The dispersion solution is characterized in that it uses distilled water, alcohol, and glycol. Nano-size anatase type titanium dioxide powder and a sol manufacturing method. In the nano-size anatase-type titanium dioxide powder and nano-sol manufacturing method using a glycol process, Adding a titanium starting material to a glycol as a solvent; A second step of obtaining a precipitate by maintaining the temperature of the glycol solution added with the titanium starting material in a temperature range of 50 ° C to 250 ° C; A third step of filtering or centrifuging and washing the precipitate; A fourth step of forming a nano-size anatase type titanium dioxide sol solution using the precipitate; A method for producing nano-size anatase-type titanium dioxide powder and a sol using a glycol process, which comprises adding an additive (tetraethyl olisosilicate) to the anatase-type titanium dioxide sol solution to produce an anatase-type titanium dioxide nano sol. In the nano-size anatase-type titanium dioxide powder and nano-sol manufacturing method using a glycol process, Titanium tetrachloride was added to 1,4-butanediol as a solvent, the concentration of 1,4-butanediol to which titanium tetrachloride was added was 0.5 M, and the temperature was maintained at a temperature range of 100 ° C to 150 ° C to obtain a precipitate. The precipitate is filtered or centrifuged and washed, and a dispersant is used in the precipitate, wherein the dispersion solution is anatase-type titanium dioxide powder and sol of a nano size, characterized in that distilled water, alcohol, and glycol are used. .