WO2000018686A1

WO2000018686A1 - Method for production of amorphous titanium peroxide solution and anatase titanium oxide sol

Info

Publication number: WO2000018686A1
Application number: PCT/JP1999/005236
Authority: WO
Inventors: Shiro Ogata; Yoshimitsu Matsui
Original assignee: Tao Inc.
Priority date: 1998-09-28
Filing date: 1999-09-27
Publication date: 2000-04-06

Abstract

In the production of an amorphous titanium peroxide solution which comprising subjecting an aqueous solution containing titanium to a neutralization reaction with a basic substance, to form a titanium hydroxide gel, washing the gel followed by cooling, reacting the gel with a peroxide to form an amorphous titanium peroxide solution, allowing to stand for aging, concentrating and purifying, and, in the production of an anatase titanium oxide sol which comprises heating the solution after the aforementioned aging to thereby convert it to an anatase titanium oxide sol, and concentrating and purifying the resultant anatase titanium oxide sol, the improvement comprising adjusting the concentration of solids in the above titanium hydroxide gel after washing to 0.2 wt.% or more and less than 1.5 wt.%. The improvement provides a practical process for producing an amorphous titanium peroxide solution and an anatase titanium oxide sol which are homogeneous and have excellent quality.

Description

Specification -

Preparation of Amorphous Titanium Peroxide Solution and Analytic Titanium Oxide Sol

Technical field

INDUSTRIAL APPLICABILITY The present invention has excellent adhesiveness, high film forming property, can form a uniform and flat thin film, and has a property that a dry film is insoluble in water. The present invention relates to a novel production method of an amorphous titanium peroxide solution, which is known to be useful as an ultraviolet cut coating, a coloring coating, etc., and particularly to a production method and a production apparatus at an industrial level. The present invention also relates to a novel method for producing an anatase-type titanium oxide sol having excellent photocatalytic ability prepared from an amorphous-type titanium peroxide solution, and particularly to a production method and a production apparatus at an industrial level.

Background art

Recently, there have been attempts to use photocatalysts to decompose, purify, and sterilize harmful substances, odorous components, oils, and other substances that occur in daily living environments, and the application range of photocatalysts is expanding rapidly. Accordingly, there is a demand for a method for supporting photocatalyst particles on any substrate firmly and for a long period of time without impairing the photocatalytic function. In particular, when an anatase-type titanium oxide sol having excellent photocatalytic function is used as a photocatalyst, improvement of its adhesiveness has been particularly demanded because the binder function to the substrate is weak.

However, in the method of the above-mentioned prior art, the adhesive strength is not sufficient, and there are few materials that can be supported for a long period of time. When it drops There was a problem. When a substrate made of an organic polymer resin is used, even if it is rutile-type titanium oxide, whose photocatalytic function is said to be weaker than the anatase type, the photocatalytic reaction proceeds, and the photochemical reaction of the organic polymer resin itself occurs. Combined with the reaction, there is a problem that it is degraded and decomposed over a long period of use. When an organic polymer resin is used as the substrate, coating with silica sol or the like has been considered in advance.However, cracks and voids are generated in the process of aggregation and drying of silica sol. However, there was a problem in performance as a binder and in function.

As a result of a search for a method for supporting photocatalyst particles on all substrates firmly and for a long period of time without impairing the photocatalytic function, the results are described in Japanese Patent Application Laid-Open No. 9-246248. As described above, when an amorphous titanium peroxide solution having no photocatalytic ability is used as a binder, the photocatalyst particles can be firmly and long-lasting on any substrate without impairing the photocatalytic function. It has been found by the inventors that they can be loaded over a period of time.

For the above-mentioned amorphous titanium peroxide solution and an analog-type titanium oxide sol having a photocatalytic activity produced from the amorphous titanium peroxide solution, a method for producing the same is disclosed in Japanese Patent Application Laid-Open No. Hei 9-171418. ing. That is, in the same publication, as a method for producing an amorphous titanium peroxide solution according to the present invention, ammonia water (1: 5) was prepared by distilling 5 cc of a 60% titanium tetrachloride solution into 500 cc of distilled water as a raw material. 9) was added dropwise to precipitate titanium hydroxide. After washing with distilled water, 10 cc of a 30% solution of hydrogen peroxide was added and stirred. A yellow viscous solution containing titanium (amorphous titanium peroxide solution) was added. It is described to produce 70 cc. The publication also states that heating this amorphous titanium peroxide solution at 80 ° C. or higher gives an anatase-type titanium oxide sol according to the present invention. Also, in the above-mentioned Japanese Patent Application Laid-Open No. 9-246248, the inventors of the present invention also disclose, as a method for producing an amorphous titanium peroxide solution according to the present invention, an aqueous solution of a titanium salt such as titanium tetrachloride, Water or an alkali hydroxide such as sodium hydroxide is added, and the resulting pale bluish white, amorphous titanium hydroxide is washed, separated, treated with a hydrogen peroxide solution, and pH 6.0 to 7.0. It is described that an amorphous titanium peroxide solution which is a yellow transparent liquid having a particle diameter of 8 to 20 nm can be obtained. The publication also describes that an anatase-type titanium oxide sol can be produced by heating an amorphous titanium peroxide solution at a temperature of 100 ° C. or more.

Disclosure of the invention

However, the production conditions for the amorphous titanium peroxide solution and the anatase titanium oxide sol described in the above publication are laboratory-level, not factory-scale, but applicable to small-scale production. However, it was found that large-scale production caused problems such as the increase in the crystal size of the analog titanium oxide sol and the precipitation of impurities due to the heat generated during the process. An object of the present invention is to provide a method for producing an amorphous titanium peroxide solution or an analog-type titanium oxide sol at an actual production level, which solves these problems.

Means for Solving the Problems The present inventors conducted intensive research to solve the above-mentioned problems, and reduced the solid concentration of titanium hydroxide gel, which is a product of the neutralization reaction between titanium tetrachloride solution and aqueous ammonia, to reduce the subsequent hydrogen peroxide concentration. The present inventors have found that the above problem can be solved by performing a peroxo-formation reaction with water, and have completed the present invention.

That is, the present invention provides a neutralization step of reacting an aqueous solution containing titanium and a basic aqueous solution, and a washing step of washing a titanium hydroxide gel generated by the neutralization reaction. Cleaning step, cooling the washed titanium hydroxide gel, peroxidation step of allowing peroxide to act on the cooled titanium hydroxide gel under cooling, and ぺ an amorphous titanium peroxide solution generated by the oxo treatment. A method of producing an amorphous titanium peroxide solution, comprising: a curing step of curing an amorphous titanium peroxide solution after curing, and a concentration and purification step of, for example, an ultrafiltration-treated amorphous titanium peroxide solution. A method for producing an amorphous titanium peroxide solution, wherein the solid content of the titanium hydroxide gel is adjusted to 0.1% by weight or more and less than 1.2% by weight before the process, and an aqueous solution containing titanium and an aqueous solution containing basic titanium. A washing step of washing the titanium hydroxide gel generated by the neutralization reaction, and cooling the washed hydroxide gel. A peroxo-forming step of allowing peroxide to act on the cooled titanium hydroxide gel under cooling; Manufacture of anatase-type titanium oxide sol consisting of a heating step of converting the titanium oxide solution into an anatase-type titanium oxide sol, and a concentration and purification step of the anatase-type titanium oxide sol generated by the heating step, for example, by ultrafiltration. The present invention relates to a method for producing an anatase-type titanium oxide sol, wherein the solid content concentration of the titanium hydroxide gel is 0.1% by weight or more and less than 1.2% by weight after the washing step and before the peroxo-forming step.

Further, the present invention provides a neutralization reaction means for reacting an aqueous solution containing titanium and a basic aqueous solution, a washing means for washing a titanium hydroxide gel produced by a neutralization reaction, and a solid content concentration of the titanium hydroxide gel after washing. A concentration adjusting means for adjusting the temperature, a means for cooling the titanium hydroxide gel having a solid concentration adjusted by, for example, a heat exchanger (cooling), and a cooling device for allowing a peroxide to act on the cooled titanium hydroxide gel. Peroxotification means consisting of a reaction tank equipped with, and amorphous titanium peroxide produced by the peroxotization reaction An amorphous type titanium oxide solution production apparatus comprising a curing means for curing a solution and an ultrafiltration means, and in particular, adopting a closed system as a neutralization reaction means and a peroxo-forming means, wherein a closed system is employed. Type Titanium peroxide solution manufacturing equipment, neutralization reaction means for reacting aqueous solution containing titanium with basic substance, washing means for washing titanium hydroxide gel generated by neutralization reaction, water after washing A concentration adjusting means for adjusting the solid content concentration of the titanium oxide gel; a means for cooling the titanium oxide gel having a solid concentration adjusted by, for example, a heat exchanger (cooling); and a peroxide added to the cooled titanium hydroxide gel. A peroxotization means consisting of a reaction tank equipped with a cooling device, for example, and an amorphous titanium peroxide produced by the peroxotation reaction An apparatus for producing an anatase-type titanium oxide sol comprising: a curing means for curing a solution; a heating means for converting an amorphous titanium peroxide solution after curing to an anatase-type titanium oxide sol; and an ultrafiltration means. The present invention relates to an apparatus for producing an anatase-type titanium oxide sol, which employs a closed system as a neutralization reaction means and a peroxo conversion means.

(Raw materials)

Examples of the raw materials used for producing the amorphous titanium peroxide solution according to the present invention include a titanium salt aqueous solution, an alkali hydroxide, a hydrogen peroxide solution, and pure water for dilution and washing, and preferably distilled water. be able to. As the titanium salt, titanium tetrachloride which is a chloride is preferable. Examples of the hydroxide include ammonia water and sodium hydroxide, and it is preferable to use ammonia water. When an aqueous solution of sodium hydroxide is used, Na ions tend to remain in the amorphous titanium peroxide solution and the anatase-type titanium oxide sol thus produced, and when these are formed into a film, titanic acid which inhibits the photocatalytic function is formed. Impurity called soda Can be. -(Dilution process)

Four highly concentrated solution of titanium chloride T i C 1 ₄ is distilled 2 0-2 0 0 times - be used by diluting with water. If used at a concentration lower than 200-fold dilution, there is a problem that the volume of the reaction vessel for performing the neutralization reaction becomes large and the cost is increased. The temperature of the liquid may increase due to the heat of the reaction during the unification, and metatitanic acid insoluble in water may precipitate. In addition, since heat is generated when diluting, it is desirable to reduce the heat generation and perform dilution.

(Neutralization reaction)

Next, titanium hydroxide is formed and precipitated by a neutralization reaction between a titanium tetrachloride solution adjusted to a predetermined concentration and aqueous ammonia. The precipitated titanium hydroxide is in a gel state due to polymerization of hydroxyl groups and hydrogen bonding. The neutralization reaction is desirably carried out so that the pH is 6.0 to 7.5, preferably pH 6.8 to 7.0. If the pH is less than 6.0, a problem arises in that the amorphous titanium peroxide solution tends to be jelly-like, but this method is used for producing an amorphous titanium peroxide viscous body. On the other hand, when the pH exceeds 7.5, repeated washing during washing with pure water becomes alkaline sooner, and the precipitated titanium hydroxide is re-dissolved to lower the yield. Furthermore, in the neutralization reaction, when the reaction is performed at a low temperature of 1 to 5 ° C., the degree of polymerization is reduced, and the film density during film formation is increased. In the neutralization reaction, it is preferable to add aqueous ammonia little by little to the titanium tetrachloride solution with stirring. (Washing)-Production · Wash the reaction product with distilled water to remove unreacted raw materials and ammonium chloride, which is a product of C 1 — ion and NH ₄ + ion, from the precipitated titanium hydroxide gel. First, the reaction solution is left for a while after the neutralization reaction, and the supernatant is discarded by decantation. Next, add about 4 to 10 times the amount of distilled water of the remaining titanium hydroxide gel (conductivity; about 40,000 x S / cm), stir well, leave to stand, and decant the supernatant. Throw away. This washing operation is repeated until the conductivity becomes 8 / XSZ cm or less. In the washing operation of titanium hydroxide, a centrifugal separation process can be used instead of decantation. In such a washing operation, it is desirable to recover titanium hydroxide contained in the wastewater after washing. As a method for recovering the titanium hydroxide, from the beginning of the washing, a titanium hydroxide gel is separated using a centrifugal separator or a decanter, and the washing wastewater is collected in a single tank, mixed with the washing solution, and then discharged. A method for recovering titanium by solid-liquid separation can be exemplified.

(Solid content adjustment)

After washing, the titanium hydroxide has a solid content concentration of 0.1% by weight or more and less than 1.2% by weight, preferably 0.3 to 1.0% by weight, particularly preferably 0.4% by weight. It is adjusted to. This concentration adjustment step is very important because it directly affects the physical properties such as the particle size of the amorphous titanium oxide sol and the titanium oxide sol which is the target product. When the solid concentration is 1.2% by weight or more, the temperature of the solution increases due to the heat of reaction in the next step of the peroxotification reaction, and the viscosity of the amorphous titanium peroxide solution increases. As described above, if the solid content is less than 1.2% by weight, and especially less than 1.0% by weight, the physical properties such as the particle size of the anatase-type titanium oxide sol However, the lower limit is preferably at least 0.1% by weight, particularly preferably at least 0.3% by weight from the viewpoint of economic efficiency such as reaction efficiency.

(Cooling)-The titanium hydroxide gel whose solid content concentration has been adjusted is cooled to 1 to 5 ° C by a heat exchanger or the like. For example, when cooled to 0 ° C or lower, the titanium hydroxide gel freezes and becomes a substance that does not undergo a peroxidation reaction such as metatitanic acid, and at 5 ° C or higher, the reaction rate in peroxotification increases as the temperature of the solution increases. It becomes faster and the liquid temperature rises due to the heat of reaction. As a result, the degree of polymerization of the amorphous titanium peroxide increases, and the viscosity of the solution increases, so that the produced amorphous titanium peroxide solution becomes difficult to coat, which is not preferable.

(Peroxo)

Next, a titanium hydroxide gel adjusted to have a solid content of 0.1% by weight or more and less than 1.2% by weight, preferably 0.3% by weight or more and 1.0% by weight or less, particularly preferably 0.4% by weight. Hydroperoxide solution is added to the mixture, and the mixture is stirred for about 12 hours while maintaining the temperature at 1 to 5 ° C to perform the peroxo-formation reaction. The amount of the hydrogen peroxide solution to be added is determined by the pH after the neutralization reaction, the pH after the washing, and the solid content of the titanium hydroxide gel. For example, a hydrogen peroxide solution having a concentration of 35% by weight is used. When used, in order to completely react the titanium hydroxide gel, it is necessary to add several times more than twice the amount of the raw material titanium tetrachloride solution (in terms of stock solution), for example, 1.25 times the amount. desirable. When the peroxidation reaction is completed, an amorphous titanium peroxide solution is generated.

(Curing) The amorphous titanium peroxide solution after the completion of the peroxo-formation reaction is then subjected to a curing process. The curing step is carried out by stirring the amorphous titanium peroxide solution generated by the peroxo-forming reaction for several days while maintaining the temperature at room temperature. Curing ends when the pH of the amorphous titanium peroxide solution becomes 6.0 or more. This curing step is desirable for the purpose of completely terminating the peroxo-forming reaction and also for naturally decomposing the hydrogen peroxide solution added excessively during the reaction to neutralize the amorphous titanium peroxide solution. . (Concentration and purification of amorphous titanium peroxide solution)

Next, the amorphous titanium peroxide solution that has undergone the curing step is concentrated by removing the miscellaneous ions by ultrafiltration. If the solution is treated with an ultrafilter, the temperature of the solution will increase. Therefore, it is preferable to perform the concentration while cooling. By the ultrafiltration treatment, an amorphous titanium peroxide solution having a solid content of 1.6 to 1.7% by weight can be obtained.

(Formation of Anaase-type titanium oxide sol)

On the other hand, the anatase-type titanium oxide sol first has a solid content of 0.1% by weight or more and less than 1.2% by weight, preferably 0.3% by weight or more and 1.0% by weight or less, particularly preferably 0.3% by weight or less, after the curing step. The amorphous titanium peroxide solution adjusted to 4% by weight is heated at a heating temperature of 100 to 200 ° C. for 1 to 20 hours, preferably at a solution temperature of 90 ° C. or higher and 100 ° C. It is prepared by heat treatment at C or lower for about 5 hours. When the amorphous titanium peroxide solution is subjected to heat treatment at a solid content of 1.6 to 1.7% by weight or more, the crystal particle size of the anatase-type titanium oxide sol is easily increased, and the photocatalytic function is increased. May decrease. At lower concentrations By performing the heat treatment, the crystal particle size of the anatase-type titanium oxide sol becomes smaller, and the photocatalytic function is improved. When heated at 100 ° C for 8 hours, a pale yellowish one with slightly suspended fluorescence is obtained.When heated at 100 ° C for 16 hours, an extremely pale yellowish one is obtained. The dry adhesion is slightly lower than that heated at 100 C for 5 hours. The viscosity of this titanium oxide sol is lower than that of an amorphous titanium peroxide solution, so that in the case of a coating liquid having a low viscosity such as a dip coating, it may be up to 2.4% by weight. Use at a higher concentration.

In addition, during the neutralization reaction, when the adjusted pH is on the acidic side, crystallization proceeds rapidly unless the heat treatment time is shortened. For example, heat treatment may be performed at 110 ° C for 4 to 5 hours. On the other hand, when the adjusted pH is on the alkaline side during the neutralization reaction, crystallization is slow, and it is desirable to increase the heating temperature, for example, by performing a heat treatment at 120 ° C. for about 6 hours. (Concentration and purification of anatase type titanium oxide sol)

Next, the anatase-type titanium oxide sol produced by the above-mentioned heat treatment is subjected to ultrafiltration treatment to remove miscellaneous ions and to be concentrated. By such an ultrafiltration treatment, an analog-type titanium oxide sol having a solid content of 2.3 to 2.4% by weight and a pH of 7.5 to 9.0 can be obtained.

(manufacturing device)

As an apparatus for producing the amorphous titanium peroxide solution and the anatase titanium oxide sol, those shown in FIGS. 1 and 2 can be exemplified.

The open-type production equipment shown in Fig. 1 is used for the production of titanium salt solution such as titanium tetrachloride, aluminum hydroxide such as ammonium hydroxide, and peroxide such as hydrogen peroxide solution. Neutralization reaction means consisting of raw material tanks 1 to 3, titanium tank solution and alkaline hydroxide dilution tanks 4 and 5, neutralization reaction tank 6 of titanium salt solution and alkali hydroxide, and neutralization A washing means comprising a washing tank 7 by decantation of the reaction product; a cooling means comprising a heat exchanger (cooling) 8; a peroxo-forming means comprising a peroxo-forming reaction tank 9 having a cooling mechanism; and a peroxo-forming reaction product. A curing means consisting of a curing tank 10 for a certain amorphous titanium peroxide solution, and an ultrafiltration device 11 consisting of an ultrafiltration device 11 for removing and condensing impurities in the amorphous titanium peroxide solution after curing Means, storage tank 12 of titanium oxide as the final product, heat exchanger (heating) 13, heat treatment for converting the amorphous titanium peroxide solution after curing into an analogous titanium oxide sol. Heating means consisting of water bath 14; heat exchanger (cooling) 15 for stopping crystallization of anatase-type titanium oxide sol produced by heat treatment; Anathese-type oxidation produced by heat treatment It comprises an ultrafiltration means comprising an ultrafiltration device 16 for removing and concentrating miscellaneous ions in titanium sol, and a storage tank 17 for titanium oxide, which is the final product. Further, a centrifuge or an ultrafilter 18 may be used instead of the washing tank 7.

In addition, the production apparatus for the closed amorphous titanium oxide solution and the analytic titanium oxide sol shown in Fig. 2 uses a tubular mixing mixer, for example, a static mixer (manufactured by Noritake Co.), as a raw material liquid. It is characterized in that it employs a closed system that replaces the mixing tank ゃ, washing tank, neutralization reaction tank, and peroxotification reaction tank. An example of the production of a titanium solution and an anatase type titanium oxide is shown.

The titanium salt aqueous solution from the raw material tank 21 of the titanium salt aqueous solution is mixed with the distilled water from the diluting distilled water storage tank 23 equipped with the distilled water producing device 22. Mix and dilute with Mixer 24. The diluent concentration is adjusted by a flow control valve 25 provided downstream of each tank. Similarly, the mixing hydroxide 27 from the alkali hydroxide hydroxide raw material tank 26 and the distilled water from the diluting distilled water storage tank 23 are mixed and diluted by the mixing mixer 27. Similarly, the concentration of the diluent is adjusted by the flow control valve 25 provided downstream of each tank.

Next, the diluted titanium salt aqueous solution and the diluted alkali hydroxide were mixed at a desired ratio by a flow rate control device 28, and a neutralization reaction was performed by a mixing mixer 29 provided downstream thereof. The pH is measured by a pH measuring device 30 and the measured value is fed back to the flow control device 28.

Titanium hydroxide, which is the product of the neutralization reaction, is then introduced into a washing water inlet pipe at the top and a drain pipe in the middle, into a sinker 31 equipped with a liquid level gauge and a solenoid valve. Then, decantation cleaning is performed. Decanting is performed by mixing the mixing mixer provided downstream of the thickener 31 by introducing washing water from the washing distilled water storage tank 33 through the washing water introduction pipe and discharging the washing wastewater from the drain pipe. After the stirring by 2, the measurement is automatically repeated until the measured value by the conductivity measuring device 34 becomes a specific value. The washing wastewater is collected in a reslurry tank 35, and the titanium hydroxide obtained by solid-liquid separation is combined with the titanium hydroxide after washing. The solid content of titanium is measured by a solid content (or specific gravity) measuring instrument 36 provided downstream of the titanium, and distilled water is added according to the measured value to obtain the desired solid content. .

The peroxide from the storage tank 37 of peroxide such as aqueous hydrogen peroxide and the titanium hydroxide having the above-mentioned desired solid concentration are mixed with a cooling mechanism prior to mixing. The mixture is mixed with a mixer 38 to perform a peroxo-formation reaction. The peroxotized reaction product is stirred and aged in a reaction aging tank 39. It is desirable that the peroxo conversion reaction be performed at 1 to 5 ° C. The amorphous titanium peroxide solution, which is a peroxidation reaction product after aging, is then cured in a curing tank 40 at room temperature for several days. Curing can be carried out even at low temperatures, but it takes time, so it is preferable to carry out curing at room temperature.

After curing, the amorphous titanium peroxide solution is purified and concentrated by an ultrafiltration device 42 having an ultrafilter 41 and a mixing mixer 38 with a cooling mechanism. Purification and concentration by the ultrafiltration unit 42 circulates the material to be processed several tens of times in Z minutes, removing wastewater from the ultrafiltration unit 41 in the circulation process, and adding distilled water to that amount. I do. After the ultrafiltration treatment, the amorphous titanium peroxide solution is filtered by a filter 43 to remove impurities, and then, for example, as a 1.7% by weight amorphous titanium peroxide solution in a product storage tank 44. Stored below 15 ° C.

On the other hand, the cured amorphous titanium peroxide solution passes through a mixing mixer 45 with a heating mechanism, is heated in a vessel 46 with a heating device, and is converted into an anatase-type titanium oxide sol. When the conversion to the titanium oxide sol is performed at a temperature of 100 ° C. or more, an autoclave can be used as a container with a heating device, if necessary. This titanium oxide sol is then subjected to ultrafiltration by an ultrafiltration device 47 in the same manner as the amorphous titanium peroxide solution. After the ultrafiltration treatment, the anatase-type titanium oxide sol is stored, for example, as a 2.4% by weight anatase-type titanium oxide sol in a product storage tank 48 at 15 ° C or lower. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a schematic illustration of an apparatus for producing an open-type amorphous titanium peroxide solution and an analog-type titanium oxide sol.

FIG. 2 is a schematic illustration of a production apparatus for a closed type amorphous titanium oxide solution and an analytic titanium oxide sol. -Best mode for carrying out the invention

Hereinafter, the present invention will be described more specifically with reference to examples, but the technical scope of the present invention is not limited to these examples. Example 1 [Open-type manufacturing apparatus]

(Production of amorphous titanium peroxide solution)

Raw material tank 1 of titanium tetrachloride T i C 1 ₄ 5 0% solution to a solution prepared by diluting (Sumitomo Shichi' Box Co., Ltd.) in dilution tank 4 to 7 0-fold with distilled water, the raw material tank 2 A solution obtained by diluting a 25% solution of ammonium hydroxide NH ₄ OH (manufactured by Takasugi Pharmaceutical Co., Ltd.) with distilled water 10 times in a dilution tank 5 is added to a neutralization reaction tank 6 at a volume ratio of 7: 1. After mixing, a neutralization reaction was performed. During the neutralization reaction, 170 mL of a dilute ammonium hydroxide solution was added little by little to 1200 L of a dilute titanium tetrachloride solution while stirring, and after the neutralization reaction, the pH was 6.8 to 7 Adjusted to 1. Dehydration after neutralization reaction ・ Leave in the concentration tank 7 for a while, discard the supernatant, add distilled water about 4 times the gel amount of the remaining titanium hydroxide T i (OH) ₄ and stir well. The supernatant was discarded. This operation was repeated seven times to remove unreacted raw materials and chloride ammonium.When the conductivity of the supernatant reached 8 S / cm, the supernatant was discarded to leave only the titanium hydroxide gel. Was. The amount of distilled water used for this washing was 1,670.

The bluish white color after washing was adjusted to a solid concentration of 1.0% by dehydration. Titanium hydroxide gel of color 6 10 L was cooled to 3 ° C, and 24 L of 35% hydrogen peroxide solution (manufactured by Nippon Peroxysite Co., Ltd.) was added twice every 30 minutes. After stirring and aging at about 5 ° C overnight, about 640 L of a yellow transparent amorphous titanium peroxide solution was obtained. This amorphous titanium peroxide solution was cured while stirring in a curing tank 9 at room temperature for 4 days to prepare an amorphous titanium peroxide solution having a solid concentration of 1.0% by weight.

Next, in order to remove and concentrate the miscellaneous ions from the cured amorphous titanium peroxide solution, an ultrafiltration apparatus 10 manufactured by Nippon Nishui Co., Ltd. was used to prevent the temperature of the solution from rising by 20 °. While cooling to C, distilled water was added to the solution until the conductivity of the waste water from the ultrafilter became 2 S / cm. By this ultrafiltration treatment, 250 L of the desired amorphous titanium peroxide solution having a solid content of 1.7% by weight and a pH of 6.5 was obtained.

(Production of anatase titanium oxide sol from amorphous titanium peroxide solution)

After the curing, the amorphous titanium peroxide solution having a solid content of 1.0% by weight was heated in a heat treatment tank 12 at 100 ° C. for 6 hours in a warm bath, and then heated. A titanium sol was obtained. The anatase-type titanium oxide sol produced by the above-mentioned heat treatment is subjected to ultrafiltration by an ultrafiltration device 13 until the conductivity becomes 2 SZ cm or less, thereby removing contaminating ions and being concentrated. Example 2 [Closed-type manufacturing apparatus] was obtained, which was a target titanium oxide sol having a solid content of 2.3 to 2.4% by weight, a pH of 7.8, and a particle size of 8 to 20 nm. ]

(Production of Amorphous Titanium Peroxide Solution)

50% titanium tetrachloride solution (Sumitomo Citix Co., Ltd.) Was 1. O four and titanium chloride aqueous solution from the raw material tank 2 1 m ^{^3,} 3. 2 O m ³ dilution of distilled water storage tank with distilled water production system 2 2 having a production capacity of 2 m ³ / h The distilled water from 23 was mixed and diluted by a mixing mixer 24, and adjusted to 70 times the dilution. Similarly, the hydroxide Anmoniumu solution from the raw material tank 2 6 1. O m ³ to 2-5% solution of hydroxide Anmoniumu (manufactured by Takasugi Pharmaceutical Co., Ltd.) is housed, from dilute water for the storage tank 24 Distilled water was mixed and diluted with a mixing mixer 27 to adjust the dilution to 10 times. Dilution was adjusted by controlling the solenoid valve according to the liquid value of the opal liquid meter. The mixing mixer used was a Suita Take Mixer (manufactured by Noritake Co.) (the same applies hereinafter).

Next, an equal amount of the diluted titanium salt aqueous solution and the diluted alkaline hydroxide were mixed by a flow control device 28, and a neutralization reaction was performed by a mixing mixer 29 provided downstream thereof. . At that time, the flow rate in the mixing mixer 29 was approximately 180 kgZh. In addition, the mixing ratio of the flow control device 28 was controlled at pH 6.9 ± 0.2 by controlling each inflow rate based on the measured value of the pH meter 30.

The titanium hydroxide gel, a neutralization reaction product, is an automated thickener 31 that combines a liquid level gauge and a solenoid valve, and has a mixing mixer 32 and a distilled water storage tank 33 for washing. It was washed by a washing mechanism. Washing was performed by adding 9 times the amount of distilled water for washing to the titanium hydroxide gel in the thickener 31 until the value measured by the conductivity measuring device 34 became 8 SZcm. The washing wastewater in the thickener 31 was collected in a reslurry tank 35, and the titanium hydroxide obtained by solid-liquid separation was combined with the washed titanium hydroxide. The washed titanium hydroxide gel was adjusted to a solid content concentration of 0.7% by weight with distilled water using a solid content concentration measuring device 36.

3 5% Hydrogen peroxide water (Nippon Parksite Co., Ltd.) storage tank 3 7 The hydrogen peroxide solution from the above and titanium hydroxide adjusted to a solid content concentration of 0.9% by weight were mixed by a mixing mixer 38 with a cooling mechanism to perform a peroxo-formation reaction. The peroxotized reaction product was stirred and aged at 3 ° C. for 18 hours in a reaction aging tank 39 equipped with a cooling device. The amorphous titanium peroxide solution, which was the peroxidation reaction product after aging, was then cured in a curing tank 40 at room temperature for about 96 hours.

The cured amorphous titanium peroxide solution was purified and concentrated by an ultrafiltration device 42 equipped with an ultrafilter 41. Purification and concentration by ultrafiltration unit 4 2 0. Circulates 8 ³ m 3 / h of processing speed, and at the same time to remove waste water from the ultrafilter 4 1 in the circulation process, and Ho添the amount of distilled water The operation was performed until the conductivity of the waste water from the ultrafilter 41 became 2 / cm. After the ultrafiltration treatment, the amorphous titanium peroxide solution is filtered through a filter 43 to remove contaminants, and then a 1.7 wt% solids concentration, pH 6.2 ammonium peroxide peroxide solution. A titanium solution was obtained. This amorphous titanium peroxide solution is stored at 15 ° C. or lower in the product storage tank 44.

(Manufacture of Anasose-type titanium oxide sol from amorphous-type titanium peroxide solution)

On the other hand, the cured amorphous titanium peroxide solution is converted to an anatase-type titanium oxide sol by heating at 100 ° C. for 5 hours in a container 46 with a heating device via a mixing mixer 45 with a heating mechanism. After filtration, the anatase-type titanium oxide sol after the filtration was subjected to an ultrafiltration treatment using an ultrafiltration device 47 in the same manner as the above amorphous titanium peroxide solution. The anatase-type titanium oxide sol that has been subjected to ultrafiltration is filtered to remove impurities, and then has a solid concentration of 2.4% by weight, a pH of 8.2, and a particle size of 8 to 20 nm. It is stored as a type titanium oxide sol in a product storage tank 48 at 15 ° C or less. Industrial applicability

According to the present invention, the amorphous titanium peroxide solution or the anatase type titanium oxide sol does not have a large crystal, does not have a danger due to heat generation, and the yield does not decrease. It can be produced at the actual production level of analytic and titanium oxide sol.

Claims

The scope of the claims -

1. A neutralization step of reacting an aqueous solution containing titanium with a basic aqueous solution, a washing step of washing the titanium hydroxide gel generated by the neutralization reaction, a step of cooling the washed titanium hydroxide gel, Peroxidation process in which peroxide acts on titanium hydroxide gel under cooling, curing process for amorphous titanium peroxide solution generated by peroxolation, and concentration and purification process of amorphous titanium peroxide solution after curing In the method for producing an amorphous titanium peroxide solution, the solid concentration of the titanium hydroxide gel should be 0.1% by weight or more and less than 1.2% by weight after the washing step and before the peroxo-forming step. A method for producing an amorphous titanium peroxide solution, comprising:

2. The method for producing an amorphous titanium peroxide solution according to claim 1, wherein the concentration and purification steps are performed by ultrafiltration.

3. A neutralization step of reacting an aqueous solution containing titanium with a basic aqueous solution, a washing step of washing the titanium hydroxide gel generated by the neutralization reaction, a step of cooling the washed titanium hydroxide gel, A peroxidation process in which peroxide acts on the titanium hydroxide gel under cooling; a curing process in which the amorphous titanium peroxide solution generated by the peroxidation is cured; and an amorphous titanium peroxide solution after curing In the method for producing an analog-type titanium oxide sol, which comprises a heating step of converting into an titanium-type sol of titanium oxide and a step of concentrating and purifying the analog-type titanium oxide sol generated in the heating step, after the washing step The anatase type wherein the solid concentration of the titanium hydroxide gel is adjusted to 0.1% by weight or more and less than 1.2% by weight before the peroxo-forming step. The process of reduction sol.

4. The process of concentration and purification is performed by ultrafiltration 4. The method for producing an analog-type titanium oxide sol according to claim 3.

5.Adjusting the neutralization reaction means for reacting the aqueous solution containing titanium with the basic aqueous solution, the washing means for washing the titanium hydroxide gel formed by the neutralization reaction, and adjusting the solid content of the washed titanium hydroxide gel. Concentration controlling means, means for cooling the titanium hydroxide gel having a controlled surface concentration, peroxo-forming means for allowing peroxide to act on the cooled titanium hydroxide gel, and amorphous type produced by the peroxo-forming reaction. An apparatus for producing an amorphous titanium peroxide solution, comprising: a curing means for curing the titanium peroxide solution; and an ultrafiltration means.

6. The apparatus for producing an amorphous titanium peroxide solution according to claim 5, wherein the means for cooling is a heat exchanger (cooling) and the means for peroxotification is a reaction tank provided with a cooling device.

7. The apparatus for producing an amorphous titanium peroxide solution according to claim 5, wherein a closed system is employed as the neutralization reaction means and the peroxotification means.

8.Adjusting the neutralization reaction means for reacting the aqueous solution containing titanium with the basic aqueous solution, the washing means for washing the titanium hydroxide gel formed by the neutralization reaction, and adjusting the solid concentration of the washed titanium hydroxide gel. Concentration adjusting means, means for cooling the titanium hydroxide gel of which the solid content concentration is adjusted, peroxo-forming means for allowing peroxide to act on the cooled titanium hydroxide gel, and amorphous peroxide generated by the peroxo-forming reaction. An anodizing titanium oxide sol comprising a curing means for curing a titanium oxide solution, a heating means for converting an amorphous titanium peroxide solution after curing to an anatase titanium oxide sol, and an ultrafiltration means. Manufacturing equipment.

9. The anatase according to claim 8, wherein the means for cooling is a heat exchanger (cooling) and the means for peroxotification is a reaction tank provided with a cooling device. Equipment for manufacturing titanium oxide sol. ―

10. The apparatus for producing an analog-type titanium oxide sol according to claim 8 or 9, wherein a closed system is employed as the neutralization reaction means and the peroxo-formation means. ―