TWI307679B - Fine pariculate titanium dioxide, and production process and use thereof - Google Patents

Description

1307679 (1) Nine, the invention belongs to the technical field of the invention. The present invention relates to fine titanium dioxide (Ti〇2) and a method for producing the same; more particularly, it relates to titanium tetrachloride as a raw material, by gas A fine particle titanium dioxide obtained by a phase method; a titanium oxide suitable for a photocatalyst or an additive of a solar cell, a polyoxyxene rubber, a dielectric material, or the like, a method for producing the same, and a use thereof.

[Prior Art] The microparticle titanium dioxide has been used for many purposes such as ultraviolet shielding materials or polyoxyxene rubber additives, dielectric materials, and cosmetic materials since ancient times. Moreover, in recent years, the application of photocatalysts or solar cells has revealed a head. The crystal form of titanium dioxide exists in the rutile type, anatase type, and brookite type. In the field of photocatalysts or solar cells, the use of the photo-electrochemical activity is superior to the rutile type of bismuth ore and brookite. type. The photocatalytic action of titanium dioxide is the decomposition of organic substances such as antibacterial bricks and self-cleaning building materials such as deodorizing fibers; the mechanism is as follows. Titanium dioxide absorbs ultraviolet light and generates electrons and holes in it. The hole reacts with the adsorbed water of the titanium dioxide to form a hydroxyl radical, and the organic matter adsorbed on the surface of the titanium dioxide particle is decomposed into titanium dioxide gas and water. (Refer to Fujisaki, Hashimoto and Ren, and Watanabe Jun, also known as "Light Purification Revolution", CMC Co., Ltd. issued in 1997). Namely, the conditions of the titanium oxide having a strong photocatalytic action are such that holes and pits are likely to easily reach the surface of the titanium oxide. High photocatalytic activity of dioxo-5-(2) 1307679 - Anatase of titanium, with few lattice defects, large particle specific surface area, etc. (Refer to Hashimoto and Ren, Fujisaki, "The Theory of Titanium Photocatalyst", CMC Co., Ltd. was issued in 1998). Practically, titanium dioxide is fixed to the surface of the substrate by an adhesive which exhibits contact energy of light contact. The photocatalyst layer requires transparency from the viewpoint of appearance concept. Therefore, the amount of titanium dioxide and the dispersibility of the powder are very important when supported on a substrate.

For the application of solar cells, since the 1991 report of the dye-sensitized solar cells combining titanium dioxide and lanthanide pigments by Gritszel of Lausanne University of Technology, etc., it has been continuously researched. [M. G r a e z e 1, N a t u r e, 353, 737, (1991)]. In the dye-sensitized solar cell, titanium dioxide has a task as a carrier for a dye and an n-type semiconductor, and is used as a dye electrode connected to a conductive glass electrode. In the dye-sensitized solar cell, the dye electrode and the counter electrode sandwich the electrolytic layer, and the dye absorbs light to generate electrons and holes. The generated electrons pass through the titanium dioxide layer to the conductive glass electrode and are emitted to the outside. On the other hand, the generated holes are transported to the counter electrode through the electrolytic layer and combined with electrons supplied through the conductive glass electrode. As one of the reasons for improving the characteristics of the dye-sensitized solar cell, the combination of titanium dioxide and pigment is easier. A crystal form of titanium dioxide which is easily bonded to a pigment, for example, an anatase type is described in Japanese Laid-Open Patent Publication No. Hei No. 0-255 863, and a brookite type is suitable for a pigment. The description of sensitized solar cells. Titanium dioxide is a good dispersibility, and its function is extremely important. Example -6- (3) 1307679 When titanium dioxide is used as a photocatalyst, the hiding power is increased when the dispersibility is poor, and it is limited to the usable use. In the field of solar cells, titanium dioxide having poor dispersibility is also difficult to transmit light, and is limited to titanium dioxide which can assist light absorption, resulting in deterioration of photoelectric conversion efficiency. In general, when the light scattering (concealing force) particle size is about 1/2 of the wavelength of visible light, the maximum particle size is reduced when the particle size is reduced (refer to Qingye, "titanium oxide"' ρ·]29Technical Publishing Co., Ltd. Company, issued in 1991).

The primary particle diameter of the titanium dioxide used in the above-mentioned fields is usually in the range of several nm to several tens of nm, and the effect on light scattering is small when the dispersibility is good. However, the light scattering of titanium dioxide which is poorly dispersed and has a large agglomerated particle size is enhanced. The particles having good dispersibility refer to particles which are not aggregated and can be stably present in a solvent in a state close to the primary particles. Titanium dioxide is an indispensable material for high-performance dielectric materials. A dielectric such as BaTi03 can be obtained by performing the following reaction under heating.

BaC03 + Ti〇2 - BaTi03 + C〇2 In order to improve the dielectric properties of BaTi03, first, it is necessary to make the particles of BaTiCh fine. When the above reaction is a solid phase reaction, the BaC03 is first decomposed at a high temperature to form BaO, and BaO is dissolved and dissolved in Ti〇2 particles to form BaTi03. Therefore, the size of the BaTi03 particles is governed by the size of the Ti 2 particles.

The chlorine ' contained in the Ti02 particles is adsorbed on each surface layer of the particles, and reacts with BaO formed during heating to form BaC. This BaCh melting acts as a flux to cause agglomeration of Ti 2 particles or BaTi 3 particles. Further, (4) 1307679, the molten flux is easily localized, and the localized portion of the flux is increased, and the quality is deviated from the other portions. Further, when the particles are agglomerated, the crystals of the BaTi〇3 particles grow into abnormal particles. The dielectric properties of B a T i Ο 3 are lowered. In the high-performance dielectric synthesis, BaO is tightly controlled by the ratio of 02 to 1:1, and the presence of chlorine causes the composition ratio to be jagged.

Further, the change in the adsorbed moisture on the surface of the particles has such a problem as impurities. When titanium dioxide is used, it is necessary to control the Ti content in a very tight manner. In particular, when the above-mentioned dielectric material is used, it is necessary to control the composition to a level of p p m . However, in industrial use, it is not easy to strictly control the ingredients. Therefore, since the water is a substance existing in the gaseous environment of the raw material treatment, it is extremely difficult to control the chemical adsorption water on the surface of the particles. The surface of titanium dioxide is substantially coated with an OH group chemically bonded to a Ti atom or a 0 atom. This OH group, in turn, forms a physical adsorption of water molecules by several layers of hydrogen bonds, and serves as a moisture-reduced moisture. (Refer to Qingye, "Titanium Dioxide", published by Tech Newspaper Publishing Co., Ltd., 1999, P · 5 4 ). However, this moisture is affected by the seasons or weather due to the repeated humidity absorption and humidity of the environment. In order to strictly control the ratio of BaO to Ti02, it is necessary to absolutely dry before the synthesis is carried out. The economic burden is difficult to estimate. Further, in order to increase the surface area equivalent to the unit mass of the fine particles, that is, the specific surface area, the amount of moisture adsorbed is also increased, and the variation in the amount of the raw material input is also increased. Recently, the tendency of micronization has been very strong. The change in the amount of input and the decrease in yield with it have become inevitable. (5) 1307679 A method for producing a dioxon is roughly classified into a liquid phase method in which titanium tetrachloride or titanium sulfate is hydrolyzed, and a gas phase method in which titanium tetrachloride is reacted with an oxidizing gas such as oxygen or water vapor. By the liquid phase method, it is possible to obtain a state in which the titanium oxide of the anatase type as a main phase cannot obtain a sol or a slurry. When used in this state, the use is limited. It is necessary to dry as a powder. After drying, there is generally the disadvantage of intense condensation. (Refer to the "Ultrafine Particles Handbook", issued by Fuji Technology Systems Co., Ltd., 1 990).

The titanium dioxide is supplied to a photocatalyst or the like, and it is necessary to forcibly crush and pulverize the titanium oxide in order to improve the dispersibility, and may cause problems such as incorporation of a treated abrasive such as pulverization or unevenness in particle size distribution. On the other hand, the titanium dioxide produced by the vapor phase method does not use a solvent, and is excellent in dispersibility compared with the liquid phase method (see "Ultrafine Particles Handbook", issued by Fuji Technology Systems Co., Ltd., 1909). There are many examples of ultrafine particles of titanium dioxide obtained by a gas phase method, for example, in a method for producing titanium dioxide by hydrolyzing titanium tetrachloride in flame, adjusting the molar ratio of oxygen, titanium tetrachloride and hydrogen to carry out a reaction. A method of obtaining a rutile type titanium oxide having a high content rate is disclosed (JP-A No. 3-255315). There is a method for producing a crystalline titanium dioxide powder by rapidly hydrolyzing a titanium tetrachloride in a high-temperature gas phase by rapidly cooling the reaction product, by making the temperature of the flame and the concentration of titanium in the material gas specific. A method of obtaining a crystalline transparent titanium oxide having an average particle diameter of 40 nm or more and 150 ηηι or less is disclosed in Japanese Laid-Open Patent Publication No. Hei 7- 3 1 6 5 3-6. A method for producing anatase-type titanium dioxide as a main phase by a vapor phase method, for example, in a gas phase reaction, 'changing a hydrogen- 9 - (6) 1307679 gas ratio of a mixed gas of oxygen and hydrogen, and adjusting the rutile type The h method containing the ratio is not disclosed; there is a rutile type content of 93⁄4 in terms of dioxins. However, the particle diameter of the exemplified titanium oxide is 〇·5 〇·6 μπι ′ than the particle size range generally referred to as ultrafine particles (Japanese Unexamined Patent Publication No. Hei No. Hei No. Hei No. Hei. The change in the drying loss of titanium dioxide 'changes the composition when using titanium dioxide in a photocatalyst or a solar cell, etc.' causes a change in quality, a decrease in performance, and a decrease in yield.

Further, impurities such as Fe, Al'Si, and S in the titanium oxide are also preferable because the quality is changed, the performance is lowered, and the yield is lowered. For example, when Fe is present in titanium dioxide, it becomes a cause of coloring, and it is not suitable for use in applications requiring transparency. When A1, S and the like are present inside the titanium dioxide particles, lattice defects are caused to lower the function as a photocatalyst or a solar cell. In the method for producing titanium dioxide, when titanium dioxide is produced by a vapor phase method using titanium tetrachloride as a raw material, ultrafine particles are easily obtained, but the chlorine derived from the raw material remains in the titanium dioxide, and it is often necessary to dechlorinate by heating or water washing. The amount of water or hydroxyl groups chemisorbed on the surface of the titanium dioxide particles is greatly affected by the treatment such as heating or water washing. Containing the remaining chlorine, etc., such as oxidation. The surface properties of titanium are not only greatly affected by the amount of adsorbed water. When heating with titanium dioxide, the sintering action or condensation action of the particles is also very much affected. Great impact. In particular, the proportion of atoms present on the surface of the degree of refinement of the titanium dioxide particles is increased, which has a great influence on the surface state. The present invention has been made to solve the above problems, and an object of the present invention is to provide a change in the moisture content of a large mass change factor in a fine particle powder of -10 (7) 1307679, which is preferably high in purity. Ultrafine titanium dioxide, and a method for its production. SUMMARY OF INVENTION [Disclosure of the Invention]

In view of the above-mentioned problems, the working colleagues of the present invention have found that in the gas phase method, by adjusting the synthesis conditions and the conditions of high purity, the basis of the surface of the ceria can be made. A sufficiently enlarged technique; thereby finding that ultrafine-particle titanium dioxide which can be produced in any environment and having a small change in quality, solves the above problems, and the present invention is a preferred embodiment of the present invention. In a gas phase method in which a gas containing titanium tetrachloride and an oxidizing gas (water vapor or a mixed gas containing oxygen and water vapor) are reacted, the heating temperature of the material gas and the type or amount of the oxidizing gas are controlled, and After the reaction, the amount of the heat loss obtained by controlling the heating temperature at the time of dechlorination treatment by heating and the amount of added water vapor is stable with the mass change in the usual environment, and in the particle size distribution and coarse particles. Ultrafine particles with specific characteristics • Titanium dioxide, and its manufacturing method. The present invention encompasses the following matters. [1] A fine particle titanium dioxide which is a fine particle titanium dioxide having a BET specific surface area of 10 to 200 m 2 /g; characterized in that 'the above 5 g of the powder is uniformly placed in a glass container having a diameter of 10 cm, in 2 (TC, the relative humidity of 80% of the environment T is allowed to stand for 5 hours, 'the quality of the pre-placement -11 - 1307679, the patent specification of the patent application No. 94127363, the revised page of the Republic of China on September 26, 1997 (8) The mass change rate is -5 mass% or more and 5% by mass or less. [2] The fine particle titanium dioxide according to the above [1], wherein the 90% cumulative mass particle size distribution diameter (D90) is 2.2 μπ or less. [3] Or the particulate titanium dioxide according to [2], wherein the distribution constant η of the Rosin-Ramer formula expressed by the following formula (1) is 1.7 or more and 3.5 or less; Rl OOexp (-bDn)

[In the formula (1), D is a particle diameter; R is a mass percentage of particles having a larger D (particle diameter) to the total particle mass; η is a distribution constant]. [4] A fine particle titanium dioxide characterized by having a BET specific surface area of a (m2/g) and a mass reduction rate (hereinafter referred to as a heat loss) in an electric furnace maintained at 900 ° C for 1 hour is X ( Mass %), the burning loss X is the range represented by the formula (2); 2.lx { α/(6 X 1 04)x 1 8 + (α-β)/(6 X 1 Ο4) χ9} χ100^ Χ^〇.25χ { α/(6 χ 1 Ο4) χ 1 8+ (α-β)/(6 χ 1 Ο4) χ 9 } χ 1 00 .........(2) [Formula (2) Medium 'cold is the BET specific surface area of the powder after burning for 1 hour in an electric furnace maintained at 900 ° C (m2/g)]. [5] A fine particle titanium dioxide characterized by a mass reduction rate (hereinafter referred to as a heat loss) when the BET specific surface area is a (m2 / g) and is heated in an electric furnace maintained at 90 ° C for 1 hour. When X (% by mass), the ignition loss X is the range represented by the formula (2'); 1. 3 χ { α / (6χ 1 04) χ 1 8 + (α-β) / (6χ 1 Ο 4) χ 9 } χ 1 〇〇g χ $ 〇·7 χ { α/ (6 χ 1 Ο4) χ 1 8+ (α-β )/(6 χ 1 〇4) χ 9 } χ 1 0 0 ..... ....(2,) [In the formula (2'), the cold is burning in an electric furnace maintained at 900 °C! Hours -12- (9) 1307679 The powder has a BET specific surface area of (m2/g)]. [6] A fine particle titanium dioxide characterized by having a BET specific surface area a (m2/g) and a mass reduction rate (hereinafter referred to as a heat loss) when it is heated in an electric furnace maintained at 9 Torr for 1 hour. (% by mass), the burning loss X is the range represented by the formula (3); 1.5 χ { α / (6 X 1 Ο 4) X 1 8 + (α-β) / (6 X 1 Ο 4) X 9 } xlOO ^ X ^0.85χ { α/ (6 x 1 Ο4) χ 1 8+ (α-β)/(6 χ 1 Ο4) χ 9 } χ 1 0 0 .........(3)

In the formula (3), the cold has a BET specific surface area (m2/g) of the powder after being burned for 1 hour in an electric furnace maintained at 90 ye. [7] A fine particle titanium dioxide characterized by having a BET specific surface area of a (m2/g) and a mass reduction rate (hereinafter referred to as a heat loss) when it is heated in an electric furnace maintained at 900 ° C for 1 hour. X (% by mass), the burning loss X is the range expressed by the formula (3'); 1·15 χ { α / (6 χ 104) χ 18 + (α - β) / (6 χ 104) χ 9} χ 1002 Χ 20 · 85 χ { α / ( 6χ 1 04)χ 1 8 + (α-β)/(6 χ 1 Ο4) χ9 } χ 1 00 .........(3,) [In the formula (3'), the call is kept The BET specific surface area of the powder after burning in an electric furnace at 900 ° C for 1 hour was (m 2 /g)]. [8] The fine particle titanium dioxide according to any one of the above items, wherein the content of Fe, Al, and S is 1 〇 mass ppm or less. [9] The fine particle titanium dioxide according to any one of the above [1], wherein the content of C1 in the powder is a mass loss of 50% by mass or less. [10] A method for producing a fine particle titanium dioxide, which comprises the first step of producing a niobium monoxide powder by performing high temperature oxygen-13-(10) 1307679 by using an oxidizing gas containing a titanium tetrachloride gas. And a second step of rotating the powder in a heating furnace while contacting the water vapor with the dioxin powder to perform dechlorination while increasing the adsorbed moisture. [11] The method for producing fine particle titanium dioxide according to the above [10], wherein the oxidizing gas is water vapor. [2] The method for producing fine particle titanium dioxide according to the above [1 1], wherein the water vapor is 1 mol to the titanium tetrachloride gas, and is 2 mol or more and 30 mol.

Below the ear. [13] The method for producing fine particle titanium dioxide according to any one of the above [10], wherein the preheating temperature of the titanium tetrachloride-containing gas and the oxidizing gas supplied to the reaction tube is 600°, respectively. C above does not reach l, l 〇〇 °C. [14] The method for producing the fine particle titanium dioxide according to any one of the above [10], wherein the second step is to introduce water of 1% by mass or more and 60% by mass or less of the titanium dioxide powder into the heating furnace. The vapor 'contacts the water vapor with the powder. [15] The method for producing fine particle titanium dioxide according to any one of the above [10], wherein the second step is to introduce water vapor of 1% by mass or more and 50% by mass or less of the titanium dioxide powder in the heating furnace. 'Let the water vapor contact the powder convection. [1] The method for producing fine titanium dioxide according to any one of the above [1], wherein the second step is to heat the titanium oxide at 150 ° C or higher at 500 ° C or lower. The method for producing the fine particle titanium dioxide according to any one of the above items, wherein the second step is a residence of the powder in the heating furnace - 14 - (11) 1307679 time is 0. · Less than 5 hours for 5 hours or more. [18] A method for producing a fine particle titanium dioxide, wherein when the powder is placed in a resin bag and packaged, the water droplets having a droplet diameter of 5 to 500 μm are sealed and stored in the storage. [19] A fine particle titanium dioxide, which is produced by the method according to any one of the above [10] to [18].

[20] A perovskite compound characterized by using the particulate titanium dioxide according to any one of the above [1] to [9] or [1 9] as a raw material [2U - a dielectric material, The titanium dioxide powder according to any one of the above [1] to [9] or [9]. [2 2] A pulverized material, which comprises the titanium dioxide powder according to any one of the above [1] to [9] or 9]. [23] A composition comprising the dioxin powder according to any one of the above [1] to [9] or [19]. [24] A photocatalyst material, which comprises the titanium dioxide powder according to any one of the above [1] to [9] or [19]. [2] A type of cosmetic material, wherein the titanium dioxide powder according to any one of the above [9] or [19] is provided. [26] A material for a solar cell, wherein the titanium dioxide powder according to any one of the above-mentioned items, wherein the titanium dioxide powder is contained in any one of the above-mentioned items. [27] A polyoxyxene rubber additive, which comprises the titanium dioxide powder according to any one of the above [1] to [9] or [1, 9]. By the preferred production method of the present invention, -15-(12) 1307679 microparticulate titanium dioxide having a small change in mass, and ultrafine-particle titanium dioxide having specific characteristics in particle size distribution and coarse particles can be obtained. By using titanium dioxide in the industrial field, by measuring the amount of ignition loss, etc., it is possible to obtain titanium dioxide which can omit the step of strictly measuring the Ti portion beforehand, and it is possible to obtain a precisely controllable amount of the reduction in manufacturing cost. Titanium dioxide.

The fine particle titanium dioxide produced in this way has a small specific surface area, and is used as a pigment of various compositions, an ultraviolet shielding material or an additive of a polyoxymethylene rubber, a clothing material, a dielectric material, or the like because of a small variation in the amount of raw material input. When a raw material such as a cosmetic material, a photocatalyst, or a solar cell is used, it is possible to exhibit a remarkable effect that it is difficult to change the quality, the performance is lowered, and the yield is lowered. [Best Mode for Carrying Out the Invention] The present invention will be described in more detail below. Usually, when titanium dioxide is used on an industrial scale, in order to strictly control the amount of raw material to be fed, in addition to measuring the amount of heat loss and drying reduction, a correction amount is added. However, the moisture absorption and dehumidification are carried out quickly, and the amount of adsorbed water is changed during the analysis to the input amount measurement, resulting in an error in the amount of feed. Therefore, even if it is corrected, it is very difficult to strictly control the amount of Ti added. The ultrafine particle titanium dioxide of the preferred embodiment of the present invention (the titanium dioxide described in the specification of the present application, all of which contains abbreviated titanium oxide) has a small change in mass. Usually, the Ti atom on the surface of the titanium oxide is chemically bonded to the OH group -16-(13) 1307679; in this OH group, a plurality of layers of water molecules are hydrogen-bonded to form a layer of physically adsorbed water. The farther the physically adsorbed water leaves the surface of the titanium dioxide, the outer layer, the weaker the bond must be. Therefore, the majority of the layers are formed, and the quality is more affected by the environment and is easy to change. On the other hand, in the preferred embodiment of the present invention, titanium dioxide is presumed to have a low level of adsorbed water and a small change in mass.

Specifically, it is characterized in that a powder having a thickness of 2 g or more and 5 g or less is placed in a glass container having a diameter of 10 cm, and is allowed to stand in an environment of 20 ° C and a relative humidity of 80% for 5 hours. The mass change rate is -5 mass% or more and 5 mass% or less, preferably -4.5 mass% or more and 4.5 mass% or less, more preferably -4 mass% or more and 4 mass% or less, based on the mass before standing. It is 2.5 mass% or more and 2 · 5 mass% or less. The fine particle titanium dioxide powder has a specific surface area of the powder measured by the BET method of from 10 to 200 m 2 /g, preferably from 20 to 180 m 2 /g: and preferably 90% of the cumulative mass particle size distribution diameter (D90) ) is 2.2 μηι or less. This type of coarse particles is of little interest and the microparticles are suitable for the intended use. Further, in the particle size distribution, the distribution constant η of the Rosin-Rammler formula expressed by the following formula (1) is 1.7 or more and 4.0 or less, preferably 1.7 or more and 3 · 5 or less. More preferably, the powder of 1 · 9 or more and 3 · 5 or less is most suitable. The distribution constant η indicates the degree of uniformity of the particle size, and the larger the number of η, the more uniform the uniformity of the particle size. R = 100exp ( -bDn) In the formula (1), D is the particle diameter; R is the mass percentage of the particles having a larger D than the total particle mass; η is the distribution constant; and b is the coefficient indicating the particle size characteristic. The Rosin-Lahm formula is described in the Handbook of Ceramic Engineering (曰本陶瓷 -17- (14) 1307679 Association Company, First Edition, pp. 596_5 98). Further, the mass reduction rate (hereinafter referred to as the ignition loss) when the specific surface area of the powder measured by the BET method is α (m2/g)' in the electric furnace maintained at 90 ° C for 1 hour is 乂 (quality) %), the burning loss X is the range represented by the formula (2); 2·1χ { α/(6 X 1 Ο4) X 1 8+ (α-β)/(6 X 1 ο4) X 9 } χ100^ Χ^0·25χ { α/(6χ1〇4)χ18 + (α-β)/(6χ104)χ9 } χ1〇〇.........(2)

Further, is the range of the formula (2'); {α/(6 X 1 Ο4) X 1 8 + (α-β)/(6 X 1 Ο4) X 9 } χ100^Χ^〇·7χ { α/(6χ104 Χ18 + (α-β) / (6χ104) χ 9 } xlOO ... (2,) is preferably the range of the formula (3); { α / (6 χ 104) χ 18 + (α-β ) /(6χ104)χ9} χ1002Χ$〇·85χ { α/(6χ 1 〇4)χ 1 8 + (α-β)/(6χ 1 04)χ9 } χ 1 〇〇........ (3) Better range of formula (3 '); 1·ΐ5χ { α/(6χ 1 04)χ 1 8 + (α-β)/(6χ 104)χ9 } χ100^Χ^〇·85χ { α/(6χ104)χ18 + (α-β)/(6χ104)χ9 } χ100 (3,) The fine particle titanium dioxide powder has a smaller mass change rate than the conventional titanium dioxide. It is suitable for use as a raw material that requires a high amount of feed. Further, in the formula (2), the formula (2), the formula (3), and the formula (3), the BET specific surface area of the powder after being heated for 1 hour in an electric furnace maintained at 900 ° C ( M2/g). Next, the definition of the formula (2), the formula (2), the formula (3) or the formula (3,) will be explained. The basic formula of the two formulas is the following formula (4). Further, it is the same in the formula (2), the formula (2'), the formula (3) or the formula (3,) -18-(15) 1307679. (αχ1〇χ1018)/(6χ1〇23)χ18+ { (α - β) χ 1 0 χ 1 0 18 } /(6χ 1 023 ) χ 0.5x18 .........(4) It is the following two formula; (a (m2/g)xi〇xi〇18(pieces/m2))/(6χ1023)[pieces/mole]xl 8 (g/mole) ....... ..(5 ) {[a - /3 ] ( m2/g) χίοχίο18 (pieces / m2) } / [6χ1023) [one / Moer

〕χ0 ' 5 χ 1 8[ g/mole] ... (6) The surface of titanium dioxide particles, rutile type about 1 〇 x 1 〇 18 (pieces / m2), anatase The OH of about 13 χΙΟ18 (pieces/m2) is present (Non-Patent Document 5). The OH on the surface of the rutile-type particles of this number is combined with H2o of one molecule, and when the heating in the form of water is measured by the heating at the time of the heat loss reduction, the mass ratio of the water detached from the particles is expressed by the formula (5). Further, when the amount of heat loss was measured, heating was performed at 900 °C. The growth of the particles is caused by heating the titanium dioxide to lower the specific surface area. This reduced amount φ is expressed by [a - yS ] ( m2 / g ). That is, the OH group is desorbed due to a decrease in the specific surface area upon heating. At this time, one molecule of water is formed from the OH group of the two molecules on the surface of the titania. The equation (6) is multiplied by 0.5. Therefore, by the surface area being lowered, the mass ratio of the water to be separated is expressed by the formula (6). The detached water used as the test for the heat loss is the sum of the formula (5) and the formula (6), that is, the formula (4). Those having the formula (4) are the formula (2), the formula (2,), the formula (3) or the formula (3,). In the fine particle titanium dioxide of the preferred embodiment of the present invention, the content of Fe, A1, and S is preferably at a mass of PPmU. Dioxane (16) 1307679 obtained by gas phase method

Titanium is based on high-purity titanium tetrachloride as a raw material to suppress the incorporation of impurities. The lower the concentration, the better, and the cost is increased in high purity from the viewpoints of the material of the device and the purity of the raw material. For industrial use, the lower limit is 2 ppm by mass, respectively. The titanium dioxide of the preferred embodiment of the present invention is characterized by high dispersibility. When the particles are generated in the gas-rich gas atmosphere, it is presumed that the surface of the particles is sufficiently covered with water molecules or OH groups. In the present invention, the particle size distribution is measured by a laser diffraction type particle size distribution measurement as an index of dispersibility. According to the "Ultrafine Particles Handbook" [Zi Tengjin 6 Supervisor, issued by Fuji Technology Systems Co., Ltd., P.93 (1 990)], there are sedimentation method, microscopic method, light scattering method, direct counting method, etc. in the measurement method of dispersibility; Among them, the sedimentation method and the direct counting method have a particle diameter of several hundred nm or more, which is not suitable for measuring the dispersibility of ultrafine particles. Further, the microscopy method is not suitable for the measurement method because the sample sample is sampled or sampled before the sample is measured to change the enthalpy. On the other hand, the light scattering method can measure the particle diameter in the range of several nm to #· number μηη, and is suitable for measurement of ultrafine particles. The order and method of measuring the particle size distribution are explained below. The particle size distribution measurement method is used to measure the particle size distribution, and as the index of dispersibility, it is preferable to use a laser diffraction type particle size distribution measuring apparatus, for example, a micro-track HRA (Nikkiso Co., Ltd.) can be used. Or SALD-2000J (made by Shimadzu Corporation). In 0.05 g of titanium dioxide, 50 ml of pure water and 100 μl of a 10% sodium hexametaphosphate aqueous solution were added to prepare a slurry, and ultrasonic irradiation (46 KHZ, 65 W) was performed for 3 minutes. This slurry was placed in a laser diffraction type particle size distribution measuring apparatus -20-(17) 1307679 (SALD-2000J, manufactured by Shimadzu Corporation), and the particle size distribution was measured. In the particle size distribution thus measured, it was judged that the hydrophilic solvent showed good dispersibility after an hour of D 9 0. It is also possible to use 50% cumulative mass particle size distribution as an indicator of dispersibility, but it is difficult to detect cohesive particles with poor dispersibility. The ultrafine particle titanium oxide of the present invention preferably has a D90 of 2.2 μη or less.

Next, the manufacturing method will be explained. The method for producing titanium dioxide by a gas phase method is known, and an oxidizing gas such as oxygen or water vapor of titanium tetrachloride is used for oxidation under a reaction condition of about 1, 〇〇〇 °c. That is, the particulate titanium dioxide is obtained. In a preferred embodiment of the present invention, a vapor phase method for producing titanium oxide by subjecting an oxidizing gas containing titanium tetrachloride gas to high temperature oxidation is employed. Preferably, the titanium tetrachloride gas which is heated above 600 ° C and does not reach 1,100 ° C and the oxidizing gas (preferably water) which is heated at not more than 1,100 ° C above 600 ° C. Vapor) is supplied to the reaction tubes separately. More preferably, the titanium dioxide obtained by the reaction is allowed to oxidize under conditions of 150 ° C or more and 500 ° C or less after being kept in the reaction tube at a temperature of not more than 1,100 ° C above 800 ° C. The degassing of the gas 'in contact with the powder convection' means that the surface of the titanium dioxide is sufficiently stable and the ultrafine particle titanium dioxide with a small change in moisture and quality changes. Dechlorination has a dry process and a wet process, which is illustrated by the dry dechlorination process. For example, a heating device such as a cylindrical rotary heating furnace, a hot air circulation type heating furnace, a flow drying furnace, or a stirring drying furnace is used to heat the titanium dioxide to remove chlorine to stabilize the surface moisture. Further, the present invention is not limited to the heating devices of -21 - (18) 1307679. Further, for example, a wet dechlorination method in which titanium dioxide is suspended in pure water to separate the chlorine which has moved to the liquid phase, and a dry dechlorination method is preferred from the viewpoint of moisture stabilization. The temperature in the reaction tube into which the gas containing titanium tetrachloride or water vapor is introduced is preferably not more than 1,1 800 at 800 °C, more preferably not more than 1, 〇〇〇 °C. By increasing the temperature inside the reaction tube, mixing and simultaneously completing the reaction

Therefore, the generation of uniform nuclei can be enhanced while the reaction area is reduced. When the temperature inside the reaction tube is less than 800 t, it is easy to obtain titanium dioxide having a high anatase content, and there is a case where chlorine is left in the titanium dioxide particles due to insufficient reaction. When the internal temperature of the reaction tube is 1,10 ° C or higher, rutile-type transfer or particle growth is carried out, and there is a tendency that low rutile type and ultrafine particles are not obtained. On the other hand, when the raw material gas is introduced into the reaction tube to carry out the reaction, the main reaction is an exothermic reaction, and there is a reaction region in which the reaction temperature exceeds 1,100 ° C. Although the device can dissipate heat somewhat, and the quenching is not performed, the titanium dioxide particles continue. It grows and the crystal form shifts to the rutile type. Therefore, in the preferred embodiment of the present invention, it is preferable to suppress 80 ° C or more and less than 1,10 (the high temperature residence time of TC is preferably 0.1 second or less, more preferably 0.0 5 seconds or less. When the high-temperature residence time exceeds 〇. 1 second, there is a tendency to transfer to rutile type or particle sintering, and there is no particular limitation, and for example, a method of introducing a large amount of gas such as cooling air or nitrogen into the reaction mixture may be employed. , or the method of spraying water, etc. Controlling the temperature inside the reaction tube below 800 ° C to less than 1,100 ° C, the ultra-fine particles with low chlorine content inside the particle can be obtained; in addition, controlling the high temperature residence time -22- (19) 1307679 It can suppress rutile transfer and grain growth in less than 1 second.

In order to keep the temperature in the reaction tube above 800 °C and less than 1, loot, the heating temperature of the raw material gas is adjusted to be more than 60 °C and above 1,100 ° below. The reaction in the tube generates heat, but when the temperature of the raw material gas is less than 600 °C, the temperature in the reaction tube is difficult to reach 800 t or more. Further, the raw material gas temperature was 1,100. (: When the above is used, although the device can dissipate heat, the temperature inside the reaction tube easily exceeds 1,1 〇〇. (: The composition of the raw material gas containing titanium tetrachloride, the inert gas of the titanium tetrachloride gas 1 mol' 0.1 to 20 moles is more preferred, and more preferably 4 to 20 moles. When the inert gas is less than this range, the density of the titanium dioxide particles in the reaction zone is increased, which is easy to aggregate and sinter, and it is difficult to obtain ultrafine titanium dioxide. When the amount is more than this range, the reactivity is lowered and the yield of titanium dioxide is lowered. The amount of water vapor reacted with the raw material gas containing titanium tetrachloride is 1 to 30 m for titanium tetrachloride. Preferably, it is preferably 5 to 25 moles. The proportion of water vapor is less than this time, and the surface of the synthesized titanium dioxide particles cannot sufficiently bind water. The surface of the titanium dioxide particles reacts slowly with moisture during long-term storage, which is a cause of quality change. At this time, although the number of nucleation increases, it is easy to obtain • Ultrafine particles, but even if it exceeds 30 m, the effect of increasing the number of nucleation is completely absent. The amount of water vapor exceeds 3 〇, although the characteristics of titanium dioxide are not affected. From the economic point of view, g ' is set to the upper limit. On the other hand, when tetrachlorochloride is used, the amount of water vapor is insufficient, and the amount of titanium dioxide which is more oxygen-deficient tends to be colored. The dechlorination of titanium dioxide by heating, Making water or hydrogen with dioxygen -23- (20) 1307679

The mass ratio (=the mass of the water vapor/the mass of the titanium dioxide, the same applies hereinafter) is 1% by mass or more and 60% by mass or less, preferably 1% by mass or more and 50% by mass. The convection of the water vapor is contacted with the titanium dioxide powder while being It is preferred to carry out the heating at a temperature of from 150 ° C to 500 ° C. More preferably, the mass ratio of water to titanium dioxide is 5% by mass or more and 40% by mass or less, and the heating temperature is 30 (TC or more and 450 ° C or less. When the heating temperature exceeds 50 (TC), sintering of titanium dioxide particles is performed to cause granules. When the heating temperature is lower than 150 °C, the efficiency of dechlorination is extremely lowered. Dechlorination is carried out by substitution reaction between chlorine on the surface of titanium dioxide and water in the vicinity of the particles or the surface hydroxyl groups of adjacent particles. In the case of heating with chlorine, it is very effective to add water vapor, and it is preferable to carry out a substitution reaction of chlorine with water or an OH group. At this time, when chlorine is substituted on the surface of titanium dioxide, it is dechlorinated without grain growth; When the surface hydroxyl groups of adjacent particles are substituted, dechlorination and grain growth are simultaneously performed. That is, when dechlorination is controlled to control grain growth, it is effective to control the mass ratio of water to titanium dioxide, and the mass ratio of water to titanium dioxide is 1 mass. When it is more than %, it is considered to be effective in suppressing the growth of the grain, and it is very suitable. The water vapor in contact with titanium dioxide can be mixed with air. The chlorine separated by titanium is effectively moved to the outside of the system. The water vapor is preferably 0.1% by volume or more in air, more preferably 5% by volume or more, and most preferably 10% by volume or more. The air containing water vapor is heated to 200 ° C or more l, 〇〇〇 ° C or less is preferred. By the dechlorination step of heating, the residence time of the powder in the rotary furnace is preferably 0.5 hours or more and less than 3 hours, more preferably 0.5 hours or more. 1 hour. This is the time required to suppress the growth of the granules and dechlorination. By -24-(21) 1307679, when the time is too short, the dechlorination is insufficient, and when it is too long, the granule growth is carried out. In the method of manufacturing, when the powder is placed in a resin bag for packaging, the water droplets are sprayed at the same time, and the method is stored in the reservoir after sealing. This method is to spray fine water droplets on the powder and carry the water droplets on the particles once. Further, in a sealed package in which a water such as a resin bag is difficult to penetrate

Stored in the material, the water droplets carried at one time are used as the adsorbent water fixers. According to this method, the water droplets can be stabilized by making the water droplets difficult to fall off in a very short time. The droplet diameter is preferably 5 to 500 μπι, more preferably 5 to 3 00 μιη. When the water droplets of the spray are as large as more than 500 μm, the water in the powder is biased, and it takes a long time for the water to become uniform. Further, when the diameter of the water droplets is less than 5 μηι, the carrier efficiency is not good and it is not practical. Water droplets in the range of 5 to 500 μηα are extremely suitable for carrying titanium dioxide of 10 to 200 m 2 /g. Other methods for producing titanium dioxide include a method of storing the powder after dechlorination in a high-humidity environment. In this case, a moisture permeable packaging material or the like can be placed and stabilized by the amount of moisture adsorbed to the target by being placed in an environment of appropriate temperature and high humidity. The appropriate temperature means an operating temperature range of about 20 to 50 ° C and a temperature of about 5 to 4 ° C in winter; the so-called high humidity is relative humidity of 60 to 9.5 %, preferably 6 0 ~ 90% meaning; when it exceeds 95%, it is easy to condense due to changes in room temperature. However, in this method, it takes a long time until it is stabilized. Further, a decompression method which is one of dechlorination methods of titanium oxide can also be used. When the pressure reduction method is carried out in a state where the water is removed from the titanium oxide at a predetermined temperature (for example, 5 to 40 ° C) and the amount of water equivalent to the amount of moisture required for the titanium oxide is supplied, the chlorine removed from the titanium oxide moves to the outside of the system. , water molecules adsorbed to the substituted titanium oxide-25- (22) (22)

The surface OH group of 1307679 can increase the adsorbed moisture of titanium oxide in a short period of time. In this case, the pressure inside the container is preferably 〇. 5 kPa or more, and more than 0 · 5 k P a or more and 2 k P a or less. Here, the degree of decompression refers to the difference between the pressure in the pressure reducer and the atmospheric pressure. Further, the upper limit of the degree of pressure reduction is not limited, and a large-scale pressure reducing device is required to increase the degree of pressure reduction. From the viewpoint of the degree of pressure reduction, the upper limit of the degree of pressure reduction is 2 kPa. However, in the case of the powder to be measured by this method, it is necessary to maintain the pressure-reduced state during continuous operation and to move the titanium oxide to the atmospheric pressure gas atmosphere in the container in the self-decompressing state, which is economically disadvantageous. The characteristic condition of the sprayed water is not particularly limited, and it is preferable to remove coarse impurities such as metal powder, and it is more preferable that pure water which removes impurities by ion exchange resin is most suitable. Although the temperature of the water can be a normal temperature cold water or a warm water of 20 to 100 ° C, it is more suitable for promoting the evaporation of fine water droplets and the adsorption of the body. The spraying method for producing water droplets of a fine diameter is not particularly limited, for example, a method of dispersing air using an ultrasonic humidifier or a heated water vapor generator, or a single fluid type or a two-fluid type spray spraying method. When the spray nozzle is used, the average particle diameter of the water droplets is 5 to 500. It is preferably a nozzle which can be controlled to 5 to 300 μm, and more preferably a nozzle of 5 to 50 μm. When the diameter of the water droplet exceeds 500 μm, the possibility of moisture in the body is increased, and it takes a long time until the water is evenly distributed. Moreover, it is easy to wet the powder, and it is possible to produce coarse particles by adhesion, which is not suitable. When the water droplet diameter is less than 5 μm, the carrier is poor and cannot be used. Water droplets in the range of 5 to 500 μm, loading. Good for the content. There are special: economic. PolyU equipment: set the filter to remove water, for powder, water steamer μτη, spray, powder need to coagulate efficiency to hold -26- (23) 1307679 I 0~20 When it is 0 m2/g of fine titanium dioxide, it is very suitable. Further, the average particle diameter of the water droplets can be measured by a method such as laser light scattering or phase Doppler (D ο p p 1 e r) laser particle analysis.

When the spray method using the two-fluid type spray nozzle is used, the characteristic conditions of the air to be used are not particularly limited, and it is preferable to remove coarse impurities in the environment through the filter, and it is more preferable to remove the remaining portion through an air dryer or the like. . Although the temperature of the air can be normal temperature, it is excellent in the effect of promoting the evaporation of fine water droplets and the adsorption of the powder when it is heated to a dry air of 20 to 100 °C. Also, a non-combustible gas such as nitrogen may be used instead of air. More preferably, the use of warm water heated to 20 to 100 ° C, and dry air or nitrogen or the like which is heated to 20 to 100 ° C, promotes evaporation of fine water droplets and promotes adsorption of the powder, and The effect of adsorbing moisture and stabilizing in a short time. The fine particle titanium dioxide of the preferred embodiment of the present invention produced as described above is suitable for various uses of fine particle titanium dioxide because it has a sharp particle size distribution and does not contain coarse particles and has a very small mass change. For example, pigments, photocatalyst effects, UV-blocking materials, UV-shielding materials, wet solar cell materials, deodorizing materials, UV-shielding materials, or polyoxygenated rubbers can be used. The additive of the product, such as barium titanate as described above, is a dielectric material such as a perovskite compound. The fine particle titanium dioxide powder or slurry of the present invention can be used. Representative uses of perovskite compounds include piezoelectric ceramics and thermoelectric ceramics. Piezoelectric ceramics used in piezoelectric actuators, BT series, PZT series -27- (24) (24)

1307679, PT series, BNT series, etc. Used in infrared sensors, etc. There are PT systems, etc. These materials all use titanium oxide as a raw material. These methods are not particularly limited, and well-known methods can be used, the second volume of Microparticle Engineering, Applied Technology p. 27~33, . Also, when using any manufacturing method, strict control of j is indispensable. Moreover, titanium oxide is also used as a hard disk or the like for honing; In this case, the concentration of solids in the honed slurry is left: important factors. Further, at the point of dispersion of the water system, the dispersion operation can be stabilized at one time. When it is used as a cosmetic raw material or a material, a photocatalyst raw material, etc., it is used as a dispersion; a dispersion of a gel, a polymer, an organic polymer, or the like; the stability; or the accuracy of the composition of the product is determined by It is preferable to stabilize the adsorbed moisture on the surface of the i particles. [Embodiment] [Examples] The present invention will be described in more detail by way of Examples and Comparative Examples. [Example 1] 20 kg/hr of titanium tetrachloride was diluted with nitrogen at 25 Nm3/hr (N is equivalent to an ideal gas standard), and then introduced into a reaction tube. The same is the steaming of 55Nm3 / hr. Thermoelectric ceramics, the manufacture of enamel. (for example, p. 190~ 1 95 ) : Sub-component is required: the condition of the horn: honing performance: stable water adsorption: the original battery for the positive battery or the poly-oxygen rubber: in the dispersion step: in the titanium oxide, the present Invented and stated, at 1,1 〇0 °C pre-gas is introduced into the reaction tube at 1,1 0 0 °c -28- (25) 1307679, and the titanium dioxide microparticles are obtained by reacting with titanium tetrachloride gas. . The fine particles are collected in a bag filter made of polytetrafluoroethylene and then introduced into an external hot rotary oven. The external hot rotary kiln is a stirring powder, and the inner side is a structure with a stirring wing. The temperature of the rotary kiln was adjusted to 400, and the residence time of the powder was adjusted to about 1 hour by adjusting the length of the temperate zone, the rotational speed, and the set angle of the furnace.

On the other hand, 20% by mass of water vapor passing through the mass of the titanium dioxide in the furnace is introduced from the powder outlet of the rotary furnace to cause the powder to be in convection with water vapor. Further, the temperature of the introduced steam is previously heated to 120 to 200. (: Left and right. The BET specific surface area of the powder thus obtained is 107 m2/g, the total chlorine content is 8,0 0 ppm by mass, F e is 2 ppm, A1 is 2 ppm or less, and s is 2 ppm or less. However, the BET specific surface area is measured by a specific surface area measuring apparatus (Flosobu II, 23 00) manufactured by Shimadzu Corporation. Here, the particle size distribution of the obtained titanium dioxide powder is measured by a laser diffraction type particle size distribution method. The result of measuring 90% of the cumulative mass particle size distribution diameter D90 was 0.9 μm. Further, 2 g of the powder was uniformly placed in a glass container having a diameter of 0 cm, at 20 ° C and a relative humidity of 80%. After standing for 5 hours, the mass change rate was found to be 2.3% by mass based on the mass before standing. The mass reduction rate at the time of burning in an electric furnace maintained at 900 ° C for 1 hour, that is, the heat loss was 5.0% by mass. The BET specific surface area of the sample after the measurement of the heat loss was 6 m2/g. Also, 'R=l〇〇exp(-bDn) is not the rosin-lamel formula -29-(26) 1307679 distribution constant η Is 2.7 [Example 2]

The 5 kg/hr titanium tetrachloride was diluted with nitrogen at 25 Nm 3 /hr to preheat at 1,100 ° C and then introduced into the reaction tube. The same is true for 55 Nm3/hr of water vapor at i,100. (: After heating, the reaction tube is introduced, and titanium dioxide microparticles are obtained by reacting with titanium tetrachloride gas. The microparticles are collected by a bag filter made of polytetrafluoroethylene and then introduced into an external thermal rotary furnace. In order to stir the powder, the inner side is provided with the structure of the stirring wing. Adjust the temperature of the rotary furnace to 400 °C 'Adjust the length of the high temperature belt, the rotation speed, and the setting angle of the furnace to adjust the residence time of the powder to about 1 On the other hand, from the powder outlet of the rotary kiln, 30% by mass of water vapor passing through the mass of titanium dioxide in the furnace is introduced to bring the powder into contact with the water vapor. Also, the temperature of the introduced steam is heated in advance. The BET specific surface area of the powder thus obtained is 1 58 m 2 /g, and the total chlorine content is 1 3,000 ppm by mass 'Fe is 2 ppm' A1 is 2 ppm or less, and S is 2 ppm or less. The ET specific surface area was measured by a specific surface area measuring apparatus (Flosobu, 2300) manufactured by Shimadzu Corporation. Here, the particle size distribution of the obtained titanium oxide powder was measured by a laser diffraction type particle size distribution method. The result of measuring the 90% cumulative mass particle size distribution diameter D90 is 〇·8 μm. Further, 2 g of the powder was uniformly placed in a glass container having a diameter of 10 cm at an environment of 20 ° C and a relative humidity of 80%. After standing for 5 hours, the mass change rate was 3.6% by mass based on the mass before -30-(27) 1307679. The mass was burned for 1 hour in an electric furnace maintained at 900 °C. The reduction rate, that is, the ignition loss is 6.5 mass%. The BET specific surface area of the sample after the measurement of the heat loss is 3.5 m2/g. Further, the Rösing-lamel formula shown by R=100exp (-bDn) The distribution constant η is 3.2.

[Example 3] 150 kg/hr of titanium tetrachloride was preheated at 900 ° C and introduced into a reaction tube. Similarly, 30 Nm3/hr of water vapor was heated to 900 °C to be introduced into the reaction tube, and by reacting with titanium tetrachloride gas, titanium dioxide fine particles were obtained. The fine particles were collected in a bag made of polytetrafluoroethylene and then introduced into an external thermal rotary furnace. The external thermal rotary furnace is a stirring powder, and the inner side is a structure in which a stirring wing is provided. Adjust the temperature of the rotary furnace at 400 °C, adjust the residence time of the powder to about 45 minutes by adjusting the length of the high temperature belt and the rotation speed 'the angle of setting of the furnace'. On the other hand, the powder outlet of the rotary furnace is introduced. The powder is convectively contacted with water vapor by a water vapor of 3% by mass of titanium dioxide in the furnace. Further, the temperature of the introduced steam is previously heated to about 120 to 200 °C. The powder thus obtained has a BET specific surface area of 12 m2/g' of a total chlorine content of 1,000 ppm by mass, Fe of 2 ppm, A1 of 2 ppm or less, and S of 2 ppm or less. However, the BET specific surface area is measured by a specific surface area measuring apparatus (Flosobu Π '23 00 ) manufactured by Shimadzu Corporation. ° -31 - (28) 1307679 Here, the particle size distribution of the obtained titanium dioxide powder is laser-based. The diffraction-type particle size distribution measurement method was carried out to determine the result of the 90% cumulative mass particle size distribution diameter D90, which was 2.2 μm. Further, 2 g of the powder was placed in a glass container having a thickness of 10 cm, and allowed to stand in an environment of 20 t and a relative humidity of 80% for 5 hours, and the mass change rate was determined based on the mass before the placement. 0.12% by mass.

The mass reduction rate in the electric furnace maintained at 900 ° C for 1 hour, i.e., the ignition loss was 0.37 mass%. The sample having a heat loss reduction was measured to have a BET specific surface area of 5 m 2 /g. Further, the distribution constant η of the Rosin-Ramer formula represented by the formula R=100exp(-bDn) is 1.7. [Example 4] 70 kg/hr of titanium tetrachloride was diluted with 20 Nm 3 /hr of nitrogen, and preheated at 900 ° C, and then introduced into a reaction tube. Similarly, 50 Nm3/hr of water vapor was introduced into the reaction tube after heating at 900 t, and titanium dioxide fine particles were obtained by reacting with titanium tetrachloride gas. The fine particles are collected by a bag filter made of polytetrafluoroethylene and then introduced into an externally heated rotating crucible. The external thermal rotary furnace is a stirring powder, and the inner side is • The structure of the stirring wing is set. Adjust the temperature of the rotary furnace to 45 ° ° C. By adjusting the length of the high temperature belt, the rotation speed, and the setting angle of the furnace, the residence time of the powder is adjusted to 45 minutes. On the other hand, from the powder outlet of the rotary kiln, 10% by mass of water vapor passing through the mass of the titanium dioxide in the furnace was introduced to bring the powder into contact with water vapor. Also, the temperature of the introduced steam is previously heated to 120~200 °c left -32- (29) 1307679 right. The powder thus obtained had a BET specific surface area of 50 m 2 /g, a total chlorine content of 5,000 ppm by mass, Fe of 2 ppm, A1 of 2 ppm or less, and s of 2 ppm or less. However, the BET specific surface area was measured by a specific surface area measuring apparatus (Flosobu, 2 3 00) manufactured by Shimadzu Corporation. Here, the particle size distribution of the obtained titanium dioxide powder is determined by a laser diffraction type particle size distribution method to determine a 90% cumulative mass particle size distribution diameter D90.

The result is 1.3 μm. Further, 5 g of the powder was uniformly placed in a glass container having a diameter of 1 〇cm, and allowed to stand in an environment of 20 ° C and a relative humidity of 80% for 5 hours, and obtained based on the mass before standing. The mass change rate was 1.8 mass ° /. . The mass reduction rate in the electric furnace maintained at 900 ° C for 1 hour, that is, the heat loss was 2.40% by mass. The sample having a heat loss reduction was measured to have a BET specific surface area of 5.6 m 2 /g.

Further, R = 1 00exp has a distribution constant η of 1.9. -BDn) The Rosin-Lamr formula shown by the formula [Example 5] 160 kg/hr of titanium tetrachloride was diluted with nitrogen gas of 23 Nm 3 /hr at 1050 . (: After preheating, the reaction tube is introduced. The same water vapor of 28 Nm3/hr is used at 1 〇50. (: After heating, it is introduced into the reaction tube, and by reacting with titanium tetrachloride gas, cerium oxide microparticles are obtained. After the collection of the bag of the four-gas-fired bakes is introduced, the external-heating rotary kiln is introduced. The external-heating rotary plug furnace is used to stir the powder, and the inner side is the structure of the stirring wing. The temperature of the rotary furnace is adjusted to 4 5 0 °C, -33- (30) 1307679 Adjust the residence time of the powder to 45 minutes by adjusting the length of the high temperature belt, the rotation speed, and the setting angle of the furnace. On the other hand, the powder outlet of the rotary furnace is introduced through 4% by mass of water vapor of the titanium dioxide in the furnace is used to convect the powder in convection with water vapor. Further, the temperature of the introduced steam is previously heated to about 120 to 200 °C.

The powder thus obtained has a BET specific surface area of 30 m 2 /g' and a total chlorine content of 25,000 mass?卩111,? 6 is 2??111, 8<1> is 2??1« or less, and 8 is 2??1« or less. However, the specific surface area of B ET was measured by a specific surface area measuring apparatus (Flosobu, 23 00) manufactured by Shimadzu Corporation. Here, the particle size distribution of the obtained titanium oxide powder was measured by a laser diffraction type particle size distribution method, and the result of measuring 90% of the cumulative mass particle size distribution diameter D90 was 0.7 μm. Further, 5 g of the powder was placed in a glass container having a thickness of 1 〇cm, and it was allowed to stand in an environment of 2 (TC, relative humidity of 80% for 5 hours, and the mass before the placement was used as a reference. The mass change rate was 1·〇% by mass.

The mass reduction rate when the temperature was kept in an electric furnace maintained at 900 ° C for 1 hour, that is, the ignition loss was 1.25 mass%. The BET « . of the sample after the heat loss reduction was measured to be 5.2 m 2 /g. Further, the distribution constant of the Rosin-Lahm's formula shown by R = 100exp(-bDn) is n = 3.4. [Example 6] On the titanium dioxide used in Example 1, 'spray droplet diameter 30 μιη water-34- (31) 1307679 • Drop, mounted in a resin bag and sealed with α, stored at room temperature adjusted to 2 5 ±3 °c. After 24 hours, the powder is placed in a glass container of 10 cm in diameter and placed in a glass container of 10 cm in diameter and allowed to stand in an environment of 20% relative humidity of 80% for 5 hours. Based on the quality, the quality change rate was calculated to be 1.4 mass. /°. [Embodiment 7]

On the titanium dioxide used in Example 4, water droplets having a droplet diameter of 30 were sprayed, sealed in a resin bag and sealed, and stored at a temperature of 25 ± 3 ° C for 24 hours; the powder was uniformly 5 g thick. Placed in a glass container of diameter, at 20%. (:, the environment was allowed to stand for 5 hours in an environment of a relative humidity of 80%, and the mass change rate was 〇833% by mass based on the mass before standing [Example 8] On the titanium oxide used in Example 5, 'spray Water droplets with a droplet diameter of 30, mounted on a resin bag and sealed, were stored 24 hours after adjusting the room temperature to 25 ± 31; 5 g of the powder was placed in a glass container having a diameter of 10 £111. , let stand for 5 hours in an environment of 20 0 'rel. humidity 80%, and determine the mass change rate 〇_74% by mass based on the mass before standing [Comparative Example 1] Make 180 kg/hr of tetrachloro The ruthenium is preheated at 900 ° C to introduce the reaction tube. Similarly, 30 Nm 3 / hr of oxygen is heated to 900 ° C and introduced into the reaction tube 'by reacting with -35- (32) 1307679 titanium tetrachloride gas to obtain titanium dioxide. The microparticles are collected by a bag filter made of polytetrafluoroethylene and then introduced into an external thermal rotary furnace. The external hot rotary snow furnace is a stirring powder, and the inner side is a structure of a stirring wing. The temperature of the rotary furnace is adjusted to 3 50. °C, by adjusting the length of the high temperature belt, the rotation speed, the setting angle of the furnace The residence time of the powder was adjusted to about 50 minutes. The powder thus obtained had a BET specific surface area of 6 m 2 /g, a total chlorine content of 100 ppm by mass, Fe of 2 ppm, A1 of 2 ppm or less, and S of 2 ppm or less.

. However, the BET specific surface area was measured by a specific surface area measuring device (Flosobu II, 2 300) manufactured by Shimadzu Corporation. Here, as a result of measuring the particle size distribution of the obtained titanium oxide powder by a laser diffraction type particle size distribution measurement, the 90% cumulative mass particle size distribution diameter D90 was 2.6 μm. Further, 5 g of the powder was placed in a glass container having a thickness of 10 cm, and allowed to stand in an environment of 20 ° C and a relative humidity of 80% for 5 hours, and the quality was changed based on the mass before the placement. The rate was 6% by mass. The mass reduction rate when the temperature was kept in an electric furnace maintained at 900 ° C for 1 hour, that is, the heat loss was 〇 6 mass %. The sample having a heat loss reduction was measured to have a BET specific surface area of 5 m 2 /g. Further, the distribution constant η of the Rosin-Lahm formula shown by R = 100exp ( -bDn ) is 1.6. [Comparative Example 2]

The 70 kg/hr titanium tetrachloride was diluted with nitrogen at 25 Nm 3 /hr and preheated at 900 ° C and introduced into the reaction tube. Similarly, 30 Nm 3 /hr of water vapor was introduced into the reaction tube after heating at 550 ° C - 36 - (33) 1307679. By reacting with titanium tetrachloride gas, titanium dioxide fine particles were obtained. The microparticles are collected in a bag made of Teflon and then introduced into an external thermal rotary furnace. Adjust the temperature of the rotary furnace to 120 °C. By adjusting the length of the high temperature belt, the rotation speed, and the setting angle of the furnace, the residence time of the powder is adjusted to about 45 minutes. The powder thus obtained has a BET specific surface area of 60 m 2 /g and a total chlorine content of 3 1,000 mass?卩1!1? 6 is 2? 111, eight 1 is 2卩卩111 or less, 8 is 2卩卩111

the following. Here, as a result of the particle size distribution of the obtained titanium oxide powder, the result of measuring the 90% cumulative mass particle size distribution diameter D90 by the laser diffraction type particle size distribution measurement was 8.8 μm. Further, 5 g of the powder was uniformly placed in a glass container having a diameter of 10 ° Cm, and allowed to stand in an environment of 20 ° C and a relative humidity of 80% for 5 hours, and the quality was changed based on the mass before the placement. The rate was 9% by mass. The mass reduction rate at the time of burning in an electric furnace maintained at 90 ° C for 1 hour, that is, the ignition loss was 5.6% by mass. The sample having a heat loss reduction was measured to have a BET specific surface area of 5.1 m2/g. Further, the distribution constant η of the Rosin-Lahm formula shown by R = 100exp ( -bDn ) is 1.2. The results of the above examples and comparative examples are shown in Table 1 and Figure 1. The "LOI theory" in Table 1 and Fig. 1 is the theoretical theory of the ignition loss; the preferred range of the straight line of Fig. 1 is 0.25 to 2.1% by mass, and more preferably 0 to 85 to 1.5% by mass. -37- (34) 1307679 t3⁄4 I嗽2酗觐| g fun to § gs ι| B pm ^ (N 2.3 3.6 0.12 1.8 1.0 1.4 0.83 0.74 Ο 〇^5 LOI theory 値χ 2.1 mass% 9.92 14.82 0.98 4.55 2.67 9.92 4.55 2.67 0.41 5.51 LOI theory 値χ〇·25 mass% ________ 1.18 1.76 0.12 0.54 0.32 1.18 0.54 0.32 0.05 0.66 LOI theory 値xl.5 mass% 7.09 10.59 0.70 3.25 1.91 1 7.09 3.25 1.91 0.29 3.94 loi mm x〇 .85 mass% 4.02 6.00 0.40 1.84 1.08 4.02 1.84 1.08 0.17 2.23 LOI Experiment 値 mass% 5.00 6.50 0.37 2.40 1.25 6.75 3.14 1.52 0.60 5.60 900°C lhr LOI Theory 値mass% 4.73 7.06 0.47 2.17 1.27 1 4.73 2.17 1.27 0.20 2.62 LOI BET m2/g ^ after measurement (N Vs 〇 · · · - BET m2 / g 107 158 12 50 30 2 ° ° ^ § Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Comparative Example 1 Comparative Example 2 (llBflMi=s)u.2liubol uo sol :i〇q -38- (35) 1307679 [Industrial Applicability] The particle size distribution suitable for various uses is sharp, And does not contain coarse particles 'and thus the titanium dioxide powder with minimal mass change. For example The use of various pigments or photocatalyst effects, ultraviolet shielding cosmetic materials, ultraviolet shielding materials, deodorizing coating materials, masking materials for shielding ultraviolet rays, additives for various products such as polyoxyxene rubber, and dielectric materials are used.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a graph showing the BET specific surface area and the amount of ignition loss of the fine particle cerium oxide produced by the examples and the comparative examples.

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Claims (1)

1307679 X. Patent Application No. 94 127363 Patent Application Revision of Chinese Patent Application Revision of the Republic of China on January 7, 1997 1. A particulate titanium dioxide which is a particulate titanium dioxide having a BET specific surface area of 10 to 200 m 2 /g; It is characterized in that 2 g or more and 5 g or less of the powder are uniformly placed in a glass container having a diameter of 10 cm, and the mass before leaving is placed in an environment of 2 (TC, relative humidity of 80% for 5 hours). The reference mass change rate is -5 mass% or more and 5% by mass or less. 2. The particulate titanium dioxide according to the first application of the patent scope, wherein 90% of the cumulative mass particle size distribution diameter (D90) is 2.2 μηι or less. The fine particle titanium dioxide of the first or second aspect, wherein the distribution constant η of the Rosin-Ramer formula expressed by the following formula (1) is 1.7 or more and 3.5 or less; R = 1 OOexp (-bDn). (1) [In the formula (1), D is the particle diameter; R is the mass percentage of the particles having a larger D (particle size) than the total particle mass; η is the distribution constant]. 4- A microparticle Titanium dioxide, characterized by a BET specific surface When a (m2/g) is a mass reduction rate (hereinafter referred to as a heat loss) when X is kept in an electric furnace maintained at 900 ° C for 1 hour, the ignition loss X is expressed by the formula (2). Range; 2.1χ{α/(6χ104)χ18 + (α-β)/(6χ104)χ9}χ100^Χ^0.25χ{α/(6 X 1〇4)x18+(α-β)/(6χ104) Χ9}X100 .........(2) 1307679 [In the formula (2), /3 is the BET specific surface area of the powder after burning for 1 hour in an electric furnace maintained at 900 ° C (m2/ g)]. 5. A fine particle titanium dioxide characterized by a mass reduction rate (hereinafter referred to as a heat loss) when the BET specific surface area is a (m2/g) and is heated in an electric furnace maintained at 900 ° C for 1 hour. When it is X (% by mass), its burning loss X is the range represented by the formula (2'); 1.3χ{α/(6χ104)χ18 + (α-β)/(6χ104)χ9}χ100^Χ^0.7χ{ α/(6χ 104)χ 1 8 + (α-β)/(6χ 1 04)χ9} X 1 00 .........(2,) [In the formula (2'), The BET specific surface area of the powder after burning for 1 hour in an electric furnace at 900 ° C is (m 2 /g )] 6. A kind of fine particle titanium dioxide characterized by a BET specific surface area of ct ( m 2 /g ) When the mass reduction rate (hereinafter referred to as "burning loss") when the temperature is maintained in an electric furnace maintained at 900 ° C for 1 hour is X (% by mass), the ignition loss X is a range represented by the formula (3); 1.5 χ { α / (6χ 1 04)χ 1 8 + (α-β)/(6χ 1 04)χ9 } χ100^Χ^0.85χ { α/(6 χ 1 Ο4) χ 1 8 + (α-β)/(6 χ 1 Ο4) χ 9 } χ 1 00 ... (3) [In the formula (3), the cold is the BET specific surface area of the powder after being heated in an electric furnace maintained at 900 ° C for 1 hour. Is (m2/g)]. 7. A fine particle titanium dioxide characterized by having a BET specific surface area a (m2/g) and a mass reduction rate (hereinafter referred to as a heat loss) when it is heated in an electric furnace maintained at 900 ° C for 1 hour is X ( The mass loss X is the range expressed by the formula (3,); 1.15 χ { α / (6 χ 104) χ 18 + (α - β) / (6 χ 104) χ 9 } χ 100 ^ Χ ^ 0.85 χ { α / ( 6 χ 1 Ο4) χ 1 8 + (α-β)/(6 χ 1 Ο4) χ9 } χ 1 00 .........(3,) 1307679 [In the formula (3,), '々 The BET specific surface area of the powder after burning for 1 hour in an electric furnace maintained at 9 ° C was (m 2 /g )]. 8. The particulate titanium dioxide according to claim 1, 2, 4, 5, 6 or 7 wherein the content of Fe, A1, and s is each 10 mass ppm or less. 9. The particulate titanium dioxide according to claim 1, 2, 4, 5, 6 or 7 wherein the content of C1 in the powder is 50% by mass or less. 10. A method for producing a fine particle titanium dioxide, characterized by comprising a first step of producing a titanium oxide powder by high-temperature oxidation using an oxidizing gas containing a titanium tetrachloride gas, and simultaneously rotating the powder in a heating furnace The second step of contacting the water vapor with the titanium dioxide powder to carry out dechlorination while increasing the adsorption of moisture. 1 1. A method of producing fine particle titanium dioxide according to claim 10, wherein the oxidizing gas is water vapor. 1 2 . The method for producing a fine particle titanium dioxide according to claim 1 , wherein the water vapor is 1 mol or less per mol of the titanium tetrachloride gas, and is 2 mol or less and 3 mol or less. The method for producing the particulate titanium dioxide according to any one of claims 1 to 2, wherein the preheating temperature of the titanium tetrachloride-containing gas and the oxidizing gas supplied to the reaction tube is 6 ο. Hey. (The above is not up to 1,1 〇〇V. 1 4 · The manufacturing method of the fine particles of the bis-2-3-1679679 titanium oxide according to any one of the claims 1 to 2, wherein the second step is Water vapor is introduced into the heating furnace to 1% by mass or more and 60% by mass or less of the titanium dioxide powder. The water vapor is brought into convection with the powder. 1 5 · The particulate titanium dioxide according to any one of the claims 1 to 12 In the manufacturing method, the second step is to introduce steam into the heating furnace to 1% by mass or more and 50% by mass or less of the titanium dioxide powder to make the water vapor and the powder convectively contact. 16. The application scope is in the range of 10 to 12 The method for producing the particulate titanium dioxide according to any one of the preceding claims, wherein the second step is to heat the titanium dioxide at 150 ° C or more and 500 t or less. 1 7 · The particulate titanium dioxide according to any one of claims 1 to 2 The manufacturing method, wherein the second step is that the residence time of the powder in the heating furnace is less than 5 hours and less than 3 hours. 1 8 . The manufacturing method of the particulate titanium dioxide according to claim 10 of the patent application scope, It is characterized in that when the powder is placed in a resin bag for packaging, the droplets having a droplet diameter of 5 to 500 μm are sprayed and stored after sealing. 1 9. A perovskite compound characterized by the use of the first to ninth application patents The particulate titanium dioxide of any one of them is used as a part of the raw material. 20. A dielectric material which is characterized by containing the titanium dioxide powder of any one of claims 1 to 9. 21. And a titanium dioxide powder containing any one of the first to ninth aspects of the invention. The composition is characterized by containing the titanium dioxide powder according to any one of claims 1 to 9. -4 A photocatalyst material comprising the titanium dioxide powder according to any one of claims 1 to 9. 24. A cosmetic material characterized by containing any one of claims 1 to 9 of the patent application scope. A titanium dioxide powder, which is characterized by containing a titanium dioxide powder according to any one of claims 1 to 9. 26. A polyoxyxene rubber additive characterized by It is a titanium oxide powder containing any one of the items 1 to 9 of the patent application.