JPWO2005054135A1 - Method for producing titanium oxide, photocatalytically active mixture, method for forming titanium oxide film using them, method for producing titanium oxide coated body, titanium oxide coated body obtained therefrom, and titanium oxide film forming solution used therefor - Google Patents

Abstract

This is a method for producing titanium oxide by allowing peroxotitanate ions, which may be derived from a reaction product of an aqueous solution of titanium salt and hydrogen peroxide, to act in the presence of an alkali. A titanium oxide film can be formed on the object. For example, a titanium oxide film is formed by attaching a peroxotitanate ion aqueous solution (for example, Ti (SO4) 2aq + H2O2) by spraying, coating, or immersing it on a film formation target (for example, cement) having an alkali on the surface. To do. The alkali may be an alkaline aqueous solution sprayed, applied, or immersed on the surface. Furthermore, it is more suitable if the surface is a porous substance. Since the titanium oxide film can be highly dispersed, the amount of titanium oxide to be used can be reduced. Further, film formation by a simple process is possible, and the manufacturing cost of the titanium oxide film forming method can be reduced.

Description

  The present invention relates to a method for producing titanium oxide, a photocatalytically active mixture, a method for forming a titanium oxide film using them, a method for producing a titanium oxide coated body, a titanium oxide coated body obtained therefrom, and a titanium oxide composition used therefor. The present invention relates to a membrane solution.

Conventionally, it has been known that titanium oxide (titanium dioxide: TiO ₂ ) has a function as a photocatalyst. When ultraviolet light hits titanium oxide, electrons are excited by the photoelectric effect, electrons and holes are generated, and move to the surface of titanium oxide. Electrons reduce oxygen in the air or water to change to superoxide, while holes oxidize surface moisture to change to hydroxyl radicals. Superoxide ions and hydroxyl radicals are called active oxygen species and exhibit a strong oxidizing action. In this state, for example, when an organic substance comes into contact with the titanium oxide surface, the superoxide ion takes away carbon of the organic substance, and the hydroxyl radical takes away hydrogen to decompose the organic substance. Carbon and hydrogen are oxidized to carbon dioxide and water, respectively.

  For example, even if nitrogen oxide (NOx), which is one of the air pollutants contained in automobile exhaust gas, is brought into contact with titanium oxide, nitrogen oxide is converted into nitrate ions by irradiation with sunlight including ultraviolet rays. It can be oxidized and removed.

  Naturally, titanium oxide also functions as a photocatalyst for decomposition of volatile organic substances such as formaldehyde, which is one of the causative substances of so-called sick house syndrome, and decomposition of oil such as heavy oil.

  Thus, since titanium oxide receives the energy of ultraviolet rays and promotes a chemical reaction, only titanium oxide present on the surface of the material that is irradiated with ultraviolet rays functions as a catalyst.

  Therefore, when using titanium oxide as a photocatalyst, it is considered that it is only necessary to provide titanium oxide only on the surface of the material.

  For this reason, conventionally, a method of forming a titanium oxide film on the surface of a material has been devised.

  As an example, a titanium oxide film forming method has been proposed in which powdered titanium oxide is kneaded with cement and sand to produce a surface layer kneaded product, thereby forming a surface layer of 2 mm to 15 mm on the object. (For example, refer to Patent Document 1).

  Also proposed is a method of forming a titanium oxide film by highly dispersing titanium oxide particles in water to form a titanium oxide-containing slurry, impregnating the titanium oxide-containing slurry on the surface of the object and drying it. (For example, see Patent Document 2).

  Further, as a solution for forming a titanium oxide film used for forming such a titanium oxide film, an anatase dispersion liquid in which anatase fine particles modified with a peroxo group are dispersed (for example, see Patent Document 3), or in a solution. Titanium oxide, titanium-containing ions and titanium ions forming solution whose cation concentration other than titanium ion is 1/2 or less of titanium concentration (see, for example, Patent Document 4), ammonium ion, chlorine ion, etc. were removed. A solution for forming titanium oxide (for example, see Patent Document 5) has been proposed.

  Furthermore, a method for forming a titania film by heating a titanium oxide forming solution containing peroxidized titanium hydroxide has also been proposed (see, for example, Patent Document 6).

In addition, an aqueous titanic acid solution obtained by adding hydrogen peroxide to a gel or sol containing titanium hydroxide is heated in the presence of the coating object to form a titanium oxide film on the surface of the coating object. A titanium film forming method is also known (see, for example, Patent Document 7 and Patent Document 8).
JP-A-9-268509 (page 2-3, FIG. 1) JP 11-33413 A (page 2-4) JP 10-67516 A (page 2-3) JP 2001-48538 A (page 2-4) JP 2000-247639 (page 2-3) JP-A-9-71418 (page 2-3) JP-A-1-224220 (page 1-3) JP 2001-97717 A (page 4-5)

  However, in the method of forming a titanium oxide film described in Patent Document 1, only the titanium oxide particles exposed on the surface of the film formation target that is irradiated with light function as a photocatalyst, and the titanium oxide embedded in the cement is a photocatalyst. It cannot function.

  Similarly, in the method of forming a titanium oxide film using the titanium oxide-containing slurry described in Patent Document 2, titanium oxide existing inside the titanium oxide particles does not function as a photocatalyst, and part of the titanium oxide is wasted. There are challenges. In this case, it has been difficult to highly disperse titanium oxide on the surface of the coating object using titanium oxide powder. That is, although the titanium oxide powder is formed from particulate titanium oxide, a technique for producing a stable dispersion with very fine particles requires a high level of technique. Therefore, it is difficult to obtain a dense titanium oxide film having good adhesion, and a large amount of titanium oxide is required to adjust the surface layer kneaded material or the titanium oxide-containing slurry. For this reason, there existed a problem that manufacturing cost will increase.

  Moreover, in the thing of patent document 3, 4, 5 and 6, many processes are required before obtaining the titanium oxide film formation solution used for formation of a titanium oxide film. That is, a step of filtering and washing titanium hydroxide or titanium oxide, a step of removing anions using an anion exchange resin, a gelation step, a separation step, etc. are necessary, and the steps are complicated. . For this reason, there existed a problem that manufacturing cost will increase.

  Moreover, in the thing of patent document 7 and 8, in order to thermally decompose the titanium peroxide compound considered to be a peroxotitanate ion to a titanium oxide, a thermal energy is required. For this reason, especially big heat energy will be needed depending on the shape of a coating target. Furthermore, there is a problem that it is difficult to form a titanium oxide film for materials that cannot be heated or existing structures. Further, when the titanium peroxide compound is thermally decomposed into titanium oxide, there is a possibility that the titanium oxides aggregate to form particles, and that the titanium oxide may precipitate on the wall surface of the reaction vessel. . Therefore, there is a problem that an extra titanium oxide is required, resulting in an increase in manufacturing cost.

  The present invention has been made in order to solve the conventional problems as described above, and is capable of reducing the amount of titanium oxide to be used and forming a titanium oxide film that can be formed by a simple process. The purpose is to provide a membrane method. This aims at reducing the manufacturing cost of the titanium oxide coated body.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that titanium oxide is produced by a simple process of reacting peroxotitanate ions with alkali.

  Moreover, since fine titanium oxide can be precipitated by this reaction, if titanium oxide is deposited on the surface of the film formation target using this reaction, the titanium oxide is deposited on the surface sufficiently to function as a photocatalyst. It has been found that an exposed thin film state or a highly dispersed titanium oxide film can be provided.

  Further, from the structural analysis by the present inventors, the titanium oxide thus produced is identified as amorphous titanium dioxide from the X-ray diffraction pattern, and this amorphous titanium dioxide has a photocatalytic function. Confirmed to be involved.

  In addition, according to the above-described reaction, for example, hardly soluble salts such as alkaline earth metal sulfates are generated as by-products in water, and these hardly soluble salts are separated from the generated titanium dioxide without being separated. It was confirmed that titanium dioxide exhibited a function as a photocatalyst in a state where the hardly soluble salt was mixed.

  In addition, the peroxotitanate ion in this case can usually be used in the form of an aqueous peroxotitanate ion solution. For example, if a titanium salt aqueous solution and hydrogen peroxide are mixed, the peroxotitanate ion is As a result, it was found that peroxotitanate ions may be either (1) the form of a peroxotitanate ion aqueous solution or (2) the combined use of a titanium salt aqueous solution and hydrogen peroxide.

  In addition, when using alkali and (1) aqueous peroxotitanate ion solution or (2) aqueous titanium salt solution and hydrogen peroxide, these chemicals may be applied sequentially even if applied to the object to be treated. However, a titanium oxide thin film can be similarly applied to the film formation target.

  Here, if the object to be treated has an affinity for alkali, after the alkali is applied to the object to be formed, (1) a peroxotitanate ion aqueous solution, or (2) a titanium salt aqueous solution and a peroxide. By applying hydrogen, after the surface of the film formation target is uniformly wetted by alkali, (1) by spraying peroxotitanate ion aqueous solution, or (2) titanium salt aqueous solution and hydrogen peroxide, A highly dispersed titanium oxide film can be obtained.

  On the other hand, when the film-forming target is expected to have higher affinity for peroxotitanate ions than alkali, the alkali may be added later. Thereby, after peroxotitanate ion is uniformly provided on the surface of the object, a highly dispersed titanium oxide film can be obtained by spraying the alkaline aqueous solution.

  In addition, according to the present invention, it has also been found that the alkali inherent in the film formation target can be used as it is as the alkali source. As a typical example of such a film formation target, a hydraulic inorganic material (for example, cement material) using calcium hydroxide as a curing source can be exemplified. However, when such a hydraulic inorganic material is exposed to the outdoors for a long period of time, it reacts with carbon dioxide in the atmosphere, so that calcium hydroxide as an alkali source becomes calcium carbonate and becomes neutralized. However, this may result in a shortage of alkali. In such a case, alkali may be additionally applied to the film formation target. In this case, the state of the titanium oxide film to be generated is grasped by applying (1) a peroxotitanate ion aqueous solution or (2) a titanium salt aqueous solution and hydrogen peroxide to the film formation target. However, an alkaline aqueous solution or the like may be additionally sprayed only when the lack of alkali is felt. Therefore, the alkali in the present invention may be present from the beginning or may be added later. In any case, a desired titanium oxide film can be formed by reacting with peroxotitanate ions.

  Therefore, the invention according to claim 1 of the present application is characterized in that a peroxotitanate ion, which may be derived from a reaction product of a titanium salt aqueous solution and hydrogen peroxide, is allowed to act in the presence of an alkali. It is a manufacturing method.

  The titanium oxide thus obtained is particulate amorphous titanium dioxide and has activity as a photocatalyst.

  The invention according to claim 2 is a photocatalyst containing titanium oxide, characterized in that peroxotitanate ions, which may be derived from a reaction product of a titanium salt aqueous solution and hydrogen peroxide, are allowed to act in the presence of an alkali. Active mixture.

  If comprised in this way, in addition to the titanium oxide obtained by making peroxotitanate ion which may be derived from the reaction material of titanium salt aqueous solution and hydrogen peroxide in presence of an alkali, a side reaction product The mixture containing can be used as a photocatalytically active mixture as it is.

  Examples of such side reaction products include salts that are sparingly soluble in water. For example, when a sparingly soluble alkaline earth metal sulfate mixture is precipitated simultaneously with titanium dioxide, the mixture functions as a photocatalyst. In addition, the alkaline earth metal sulfate mixture can function as a binder between titanium oxide or titanium oxide and another substance (for example, a film formation target).

  Furthermore, since this photocatalytically active mixture is essentially formed into particles mainly composed of titanium oxide, it can be used as a dispersed or redispersed slurry, for example.

  The invention according to claim 3 is characterized in that a peroxotitanate ion, which may be derived from a reaction product of a titanium salt aqueous solution and hydrogen peroxide, is allowed to act in the presence of an alkali. Is the method.

  If comprised in this way, a peroxotitanate ion and an alkali will act, and a titanium oxide film can be formed into a highly dispersed film on the surface of a film-forming object.

  According to the method for forming a titanium oxide film according to the present invention, a highly dispersed titanium oxide film can be formed, so that the amount of titanium oxide to be used can be reduced. In addition, since the film formation by a simple process is possible, the manufacturing cost can be reduced.

  According to a fourth aspect of the present invention, the peroxotitanate ion is applied to the film formation target in the form of (1) an aqueous solution, or (2) an aqueous solution of a titanium salt and hydrogen peroxide. 4. The method for forming a titanium oxide film according to claim 3, wherein the film is derived from a reactant and applied to the film formation target in the form of an aqueous solution of titanium salt and hydrogen peroxide.

  If comprised in this way, peroxotitanate ion is provided to the film-forming target in the form of (1) aqueous solution, or (2) the form of titanium salt aqueous solution and hydrogen peroxide with respect to the film-forming target In this case, a titanium oxide film can be formed using peroxotitanate ions generated by the action of a titanium salt and hydrogen peroxide.

  The invention according to claim 5 is the film formation of the titanium oxide film according to claim 4, wherein the alkali is derived from the film formation target and / or applied to the film formation target. Is the method.

  If comprised in this way, the provision process of an alkali can be abbreviate | omitted, the provision amount of an alkali can be reduced, and also a titanium oxide film can be formed also on the surface which does not exhibit an alkali.

  The invention according to claim 6 is the method for forming a titanium oxide film according to claim 5, wherein the alkali and peroxotitanate ions are simultaneously or sequentially applied to the object to be formed. It is.

  If comprised in this way, when giving simultaneously alkali and a peroxotitanate ion with respect to the film-forming target object, since it can provide in one process, a process can be simplified.

  In addition, when alkali and peroxotitanate ions are sequentially applied, since titanium oxide is deposited on the surface of the film formation target, a highly dispersed titanium oxide film is easily formed. Thereby, for example, even when the film formation target is a microporous porous material, a titanium oxide film can be reliably applied to the surface or in the micropores in the vicinity of the surface.

  The invention according to claim 7 is the method for forming a titanium oxide film according to claim 6, wherein after the peroxotitanate ion aqueous solution is applied to the film formation target, an alkaline aqueous solution is applied. is there.

  If comprised in this way, a film formation target object has affinity with a peroxotitanate ion aqueous solution by providing alkaline aqueous solution after providing a peroxotitanate ion aqueous solution with respect to a film formation target object. In this case, the peroxotitanate ion aqueous solution is easily applied uniformly to the film formation target (highly dispersed), and a highly dispersed titanium oxide film can be formed by applying alkali thereafter.

  In addition, since deposition of titanium oxide starts when alkali is applied to the film formation target, each titanium oxide film formation solution has its fineness even when the film formation target is a microporous porous material. It can be reliably applied to the surface of the pores, and a titanium oxide film can be reliably applied to the surface of the micropores.

  The invention according to claim 8 provides the titanium oxide film according to claim 6, wherein an alkaline aqueous solution is applied after a mixture of a titanium salt aqueous solution and hydrogen peroxide is applied to the film formation target. This is a film forming method.

  If comprised in this way, the peroxotitanate ion produced | generated by providing the liquid mixture of a titanium salt aqueous solution and hydrogen peroxide to the film-forming target object will act on the alkali aqueous solution provided at the end, and a titanium oxide film will be formed. A film can be formed.

  In addition, when the film formation target has an affinity with the liquid mixture, the first liquid mixture is easily applied uniformly to the film formation target (highly dispersed), and the alkali applied last. By this action, a highly dispersed titanium oxide film can be formed.

  In addition, since deposition of titanium oxide starts when alkali is applied to the film formation target, each titanium oxide film formation solution has its fineness even when the film formation target is a microporous porous material. It can be reliably applied to the surface of the pores, and a titanium oxide film can be reliably applied to the surface of the micropores.

  The invention according to claim 9 is characterized in that after the titanium salt aqueous solution is applied to the film formation target, hydrogen peroxide solution is applied, and then the alkaline aqueous solution is applied. This is a method of forming a titanium film.

  According to this structure, after the titanium salt aqueous solution is applied to the film formation target, the peroxotitanate ion generated by applying the hydrogen peroxide solution acts on the alkaline aqueous solution that is finally applied to oxidize. A titanium film can be formed.

  Further, when the film formation target has affinity with the titanium salt aqueous solution, the titanium salt aqueous solution applied first is easily applied uniformly (highly dispersed) to the film formation target, and is finally applied. A highly dispersed titanium oxide film can be formed by the action of alkali.

  In addition, since deposition of titanium oxide starts when alkali is applied to the film formation target, each titanium oxide film formation solution has its fineness even when the film formation target is a microporous porous material. It can be reliably applied to the surface of the pores, and a titanium oxide film can be reliably applied to the surface of the micropores.

  The invention according to claim 10 is characterized in that after the hydrogen peroxide solution is applied to the film formation target, a titanium salt aqueous solution is applied, and then an alkaline aqueous solution is applied. This is a method of forming a titanium film.

  If comprised in this way, the peroxotitanate ion produced | generated by providing a titanium salt aqueous solution after providing hydrogen peroxide water to the film-forming target object will react with the alkaline aqueous solution provided last, and will oxidize. A titanium film can be formed.

  In addition, when the film formation target has affinity with hydrogen peroxide solution, the hydrogen peroxide solution applied first is easily applied uniformly (highly dispersed) to the film formation target, and finally A highly dispersed titanium oxide film can be formed by applying the alkali to be applied.

  In addition, since deposition of titanium oxide starts when alkali is applied to the film formation target, each titanium oxide film formation solution has its fineness even when the film formation target is a microporous porous material. It can be reliably applied to the surface of the pores, and a titanium oxide film can be reliably applied to the surface of the micropores.

  The invention according to claim 11 is the method for forming a titanium oxide film according to claim 6, wherein a peroxotitanate ion aqueous solution and an alkaline aqueous solution are simultaneously applied to the film formation target.

  This configuration simplifies the process by simultaneously applying a peroxotitanate ion aqueous solution and an alkaline aqueous solution to the film formation target, thereby providing a film forming solution consisting of two liquids in a single step. Can be made.

  The invention according to claim 12 is the method for forming a titanium oxide film according to claim 6, wherein a titanium salt aqueous solution, a hydrogen peroxide solution, and an alkaline aqueous solution are simultaneously applied to the film formation target.

  If comprised in this way, the film formation solution which consists of three liquids can be provided in one process by simultaneously providing titanium salt solution, hydrogen peroxide solution, and alkaline solution to the object for film formation, so the process is simplified. It can be made.

  The invention according to claim 13 is a method for forming a titanium oxide film, characterized in that a titanium oxide film is formed by attaching a peroxotitanate ion aqueous solution to a film formation target having an alkali on the surface. It is.

According to this structure, for attaching pel oxo titanic acid ion aqueous solution film-forming target having an alkali on the surface of titanium oxide by the reaction with alkali and peroxide oxo titanate ion solution (TiO ₂₎ is produced Thereby, a titanium oxide film is formed.

  Therefore, according to this method for forming a titanium oxide film, it is possible to easily form a titanium oxide film on the surface of an object to be formed without requiring a heating step or an ion exchange step.

  In addition, since peroxotitanate ions are reacted with alkali, titanium oxide can be easily highly dispersed as compared with the case of using a titanium oxide aqueous solution or titanium oxide gel containing titanium oxide.

  Therefore, the amount of titanium oxide required for film formation can be reduced, and the manufacturing cost can be reduced.

  The invention described in claim 14 is characterized in that the peroxotitanate ion aqueous solution is a mixed aqueous solution of a titanium salt aqueous solution and a hydrogen peroxide solution. This is a film forming method.

  According to this configuration, the peroxotitanate ion aqueous solution is a mixed aqueous solution of a titanium salt aqueous solution and a hydrogen peroxide solution. An aqueous ionic solution can be obtained.

  The invention described in claim 15 is characterized in that a titanium oxide aqueous solution is attached to a film formation target having alkali on the surface, and then a hydrogen peroxide solution is attached to form a titanium oxide film. This is a method for forming a titanium oxide film.

  If comprised in this way, after attaching titanium salt aqueous solution, in order to attach hydrogen peroxide solution, peroxotitanate ion is first produced | generated by titanium salt aqueous solution and hydrogen peroxide solution. This peroxotitanate ion reacts with the alkali on the surface to produce titanium oxide, whereby a titanium oxide film can be formed on the surface of the film formation target.

  Therefore, according to the method for forming a titanium oxide film of the present invention, a titanium oxide film in which titanium oxide is highly dispersed can be easily formed on the surface of the film formation target without requiring a heating step or an ion exchange step. A film can be formed.

  Moreover, since the generated peroxotitanate ions are reacted with the alkali, it is possible to easily disperse titanium oxide easily as compared with the case of using a titanium oxide aqueous solution or titanium oxide gel containing titanium oxide. .

  Therefore, the amount of titanium oxide required for film formation can be reduced, and the manufacturing cost can be reduced.

  The invention described in claim 16 is the method for forming a titanium oxide film according to claim 14 or 15, wherein the titanium salt is titanium sulfate or titanium chloride.

  If comprised in this way, since a titanium salt is a titanium sulfate or a titanium chloride, it can be easily dissolved in water and a titanium salt aqueous solution can be obtained easily.

  The invention described in claim 17 is the method for forming a titanium oxide film according to any one of claims 13 to 16, wherein the object to be formed is made of an alkali-containing material. .

  If comprised in this way, since the film-forming target object consists of an alkali containing material, it does not require the separate process of hold | maintaining an alkali on the surface of a film-forming target object, and can reduce the film-forming process of a titanium oxide film. it can.

  The invention described in claim 18 is characterized in that the surface is formed of an alkali-containing material held on the film formation target. This is a method for forming a titanium oxide film.

  If comprised in this way, since the surface is formed from the alkali containing material hold | maintained at the film-forming target object, even if the film-forming target object has a property which is hard to hold | maintain an alkali, Thus, a titanium oxide film can be formed on the object to be formed.

  The invention described in claim 19 is the method for forming a titanium oxide film according to claim 17 or 18, wherein the alkali-containing material is cement or fly ash.

  With this configuration, since the alkali-containing material is cement or fly ash, if the alkali-containing material is cement, a titanium oxide film can be easily formed on a structure or the like. If it is fly ash, the powder which can decompose | disassemble organic substances, such as an oil component mixed in the soil etc., can be obtained.

  The invention according to claim 21 is characterized in that the surface is made of a porous material, and the alkali is supported on the surface formed from the porous material. 2. A method for forming a titanium oxide film according to item 1.

  The invention according to claim 20 is the method for forming a titanium oxide film according to any one of claims 3 to 19, wherein the object to be formed is made of a porous material.

  In the invention according to claim 21, configured as described above, since the film formation target is made of a porous material, the surface area of the titanium oxide film can be obtained by forming the titanium oxide film toward the surface opening of the porous material. Can earn.

  If comprised in this way, since the surface consists of a porous material, an alkali can be carry | supported by many holes with which this porous material is provided.

  Therefore, by applying an aqueous solution containing an alkali, dipping, spraying, or the like, the alkali can be easily held on the surface of the film formation target.

  The invention described in claim 22 is characterized in that the porous substance is any one or a mixture of concrete, silica gel, alumina, talc, calcium carbonate, and sand. The method for forming a titanium oxide film according to 20 or 21.

  If comprised in this way, since the porous substance is any one or a mixture of two or more of concrete, silica gel, alumina, talc, calcium carbonate, or sand, the product produced thereby is not irradiated with ultraviolet rays. Sometimes, nitrogen oxides, bacteria, etc. are adsorbed, and when irradiated with ultraviolet rays, nitrogen oxides, bacteria, etc. can be oxidized or decomposed by the photocatalytic function of the titanium oxide film.

  In the invention described in claim 23, the alkali is any one of an alkali metal hydroxide, an alkaline earth metal hydroxide, or ammonia. The method for forming a titanium oxide film according to any one of the above items.

  In the invention described in claim 24, the titanium salt is titanium sulfate, and the alkaline earth metal hydroxide is any one of calcium hydroxide, strontium hydroxide, and barium hydroxide. 24. The method for forming a titanium oxide film according to claim 23.

  With this configuration, the titanium salt is titanium sulfate, and the alkaline earth metal hydroxide is any one of calcium hydroxide, strontium hydroxide, and barium hydroxide. , Calcium sulfate, strontium sulfate, or barium sulfate is formed. This calcium sulfate, strontium sulfate, or barium sulfate functions as a binder for titanium oxide (titanium dioxide) without substantially reducing the photocatalytic ability of the titanium oxide film. In addition, since calcium sulfate, strontium sulfate, or barium sulfate is hardly soluble in water, titanium oxide in the titanium oxide film is hardly eluted by rain or the like, and the durability of the titanium oxide film can be improved.

  In the invention described in claim 25, the titanium salt is titanium chloride, and the alkaline earth metal hydroxide is any one of calcium hydroxide, strontium hydroxide, and barium hydroxide. 24. The method for forming a titanium oxide film according to claim 23.

  According to this structure, the titanium salt is titanium chloride, and the alkaline earth metal hydroxide is any one of calcium hydroxide, strontium hydroxide, and barium hydroxide. In this case, water-soluble sodium chloride, calcium chloride or barium chloride is formed. Therefore, chlorine (chlorine compound) can be easily removed simply by washing with water.

  According to a twenty-sixth aspect of the present invention, a titanium oxide film-forming solution containing peroxotitanate ions, which may be derived from a reaction product of the aqueous titanium salt solution and hydrogen peroxide, is applied as a film formation target in the form of a spray. 26. The method for forming a titanium oxide film according to claim 3, wherein the titanium oxide film is provided.

  The titanium oxide film-forming solution can be applied, dipped, or applied by any application method such as spraying, but if applied in the form of a spray, it is more uniform and high for the film-forming target. A dispersed titanium oxide film can be formed.

  A twenty-seventh aspect of the present invention is a method for manufacturing a titanium oxide coated body, wherein the titanium oxide film forming method according to any of the third to twenty-sixth aspects is used.

  A twenty-eighth aspect of the invention is a titanium oxide coated body obtained by the titanium oxide film forming method according to any of the third to twenty-sixth aspects or the titanium oxide coated body manufacturing method according to the twenty-seventh aspect.

  A twenty-ninth aspect of the present invention is a titanium oxide film-forming solution comprising two liquids, a peroxotitanate ion aqueous solution and an alkaline aqueous solution.

  A thirty-third aspect of the invention is a titanium oxide film-forming solution comprising two solutions of a mixed solution of an aqueous solution of titanium salt and hydrogen peroxide and an alkaline solution.

  A thirty-first aspect of the present invention is a titanium oxide film-forming solution comprising three liquids of an aqueous titanium salt solution, a hydrogen peroxide solution and an alkaline solution.

  According to the present invention, peroxotitanate ions and an alkali can act to produce titanium oxide or a mixture that functions as a photocatalyst containing titanium oxide, and the surface of a film formation target can be obtained using these reactions. In addition, a titanium oxide film can be formed. This method for forming a titanium oxide film can reduce the amount of titanium oxide to be used and enables film formation by an easy process, thereby reducing the manufacturing cost.

According to the method for forming a titanium oxide film according to one aspect of the present invention, an aqueous peroxotitanate ion solution is attached to a film formation target in the presence of an alkali. As a result, titanium oxide (TiO ₂ ) is generated, whereby a titanium oxide film is formed.

  In addition, according to another method of forming a titanium oxide film of the present invention, after attaching a titanium salt aqueous solution in the presence of alkali, a hydrogen peroxide solution is attached. Peroxotitanate ions are generated by hydrogen water. Then, this peroxotitanate ion reacts with alkali to produce titanium oxide, whereby a titanium oxide film can be formed on the surface of the film formation target.

  In addition, according to another method of forming a titanium oxide film of the present invention, since alkali and peroxotitanate ions are sequentially applied, titanium oxide is deposited on the surface of the film formation object, so that high dispersion is achieved. The feature is that the formed titanium oxide film is easily formed. Thereby, for example, even when the film formation target is a microporous porous material, a titanium oxide film can be reliably applied to the surface or in the micropores in the vicinity of the surface.

  In addition, according to another titanium oxide film forming method of the present invention, alkali and peroxotitanate ions are simultaneously applied to the object to be formed, and therefore can be applied in a single process, thus simplifying the process. be able to.

  Therefore, according to these methods for forming a titanium oxide film, a titanium oxide film can be easily formed on the surface of a film formation target without requiring a heating step or an ion exchange step.

  In addition, since peroxotitanate ions are reacted in the presence of alkali, titanium oxide can be easily highly dispersed as compared with the case of using a titanium oxide aqueous solution or titanium oxide gel containing titanium oxide.

  Therefore, the amount of titanium oxide required for film formation can be reduced, and the manufacturing cost can be reduced.

It is a diagram showing the relationship between the pel oxo titanate ion aqueous H ₂ O ₂ / Ti (molar ratio) and NO adsorption rate. It is a diagram showing the relationship between the pel oxo titanate ion aqueous H ₂ O ₂ / Ti (molar ratio) of NO light adsorption rate. It is the figure which showed NO adsorption | suction speed | velocity | rate for every alkali. It is the figure which showed the NO photo-oxidation rate for every alkali. It is the figure which showed the relationship between Ba (OH) ₂ / Ti (molar ratio) and NO adsorption rate in barium hydroxide and peroxotitanate ion aqueous solution. It is the figure which showed the relationship between Ba (OH) ₂ / Ti (molar ratio) and NO photo-oxidation rate in barium hydroxide and peroxotitanate ion aqueous solution. It is the figure which showed the X-ray-diffraction result of the deposit produced | generated by mixing alkaline aqueous solution and peroxotitanate ion aqueous solution.

  An embodiment of the present invention will be described.

  One example of a preferred embodiment of the present invention is that a peroxotitanate ion, which may be derived from a reaction product of a titanium salt aqueous solution and hydrogen peroxide, is allowed to act in the presence of an alkali on a film formation target. And forming a titanium oxide film.

According to this structure, it is possible to highly disperse readily titanium oxide (TiO ₂₎ on the surface of the object to be film and pel oxo titanate ion and alkali acts, thereby, oxidation of low-cost A titanium film can be formed.

  Here, the peroxotitanate ion may be (1) applied to the film formation target in the form of an aqueous solution, or (2) any of the combined use of a titanium salt aqueous solution and hydrogen peroxide.

  (2) When applied in combination, it may be applied separately to the film formation target as a two-component solution in the form of an aqueous solution of titanium salt and hydrogen peroxide. You may provide as one liquid with the form of a liquid mixture. In any case, the titanium salt aqueous solution and hydrogen peroxide act to give peroxotitanate ions, and the peroxotitanate ions act with alkali to form a highly dispersible titanium oxide film. .

  Here, the titanium oxide film that can be highly dispersed means that the titanium oxide particles are highly dispersed on the surface of the coating object. In other words, such titanium oxide particles are coated. Due to the high dispersion on the surface of the object, when the surface of the coated object is irradiated with light, the titanium oxide formed on the surface is efficiently irradiated with light, and the characteristics of titanium oxide as a photocatalyst are improved. It is possible to make the most of it.

  The alkali used in the present invention may be derived from an object to be formed, or may be an alkali provided later. In the case of using an alkali based on the film formation target, the alkali application step can be omitted or the amount of alkali applied can be reduced.

  Further, when the film formation target does not exhibit alkalinity, the alkali may be imparted to the film formation target, whereby the titanium oxide film is also applied to the surface of the film formation target that does not exhibit alkali. Can be formed.

If a peroxotitanate ion aqueous solution is attached to a film-forming target having an alkali on the surface, the surface alkali and peroxotitanate ions react to produce titanium oxide (TiO ₂ ). A titanium oxide film can be formed on the surface of the film object.

Alternatively, a hydrogen peroxide solution (H ₂ O ₂ aqueous solution) may be attached after an aqueous solution of a soluble titanium salt is attached to a film formation target having alkali on the surface. According to this film forming method, after attaching the soluble titanium salt aqueous solution, the hydrogen peroxide solution is attached, so that peroxotitanate ions are first generated by the soluble titanium salt aqueous solution and the hydrogen peroxide solution. This peroxotitanate ion reacts with the alkali on the surface to produce titanium oxide, whereby a titanium oxide film can be formed on the surface of the film formation target.

  When the film formation target does not exhibit alkalinity, or exhibits alkalinity but the amount of alkali is not sufficient, alkali can be additionally provided. In such a case, the order of application of alkali and peroxotitanate ions to the film formation target is not particularly limited.

  For example, the film-forming solution containing alkali and peroxotitanate ions may be applied to the film-forming target simultaneously or sequentially.

  In the case where a film-forming solution containing an alkali and peroxotitanate ions is simultaneously applied to a film-forming target, the process can be simplified because it can be applied in a single process.

  In addition, when alkali and peroxotitanate ions are sequentially applied, since titanium oxide is deposited on the surface of the film formation target, a highly dispersed titanium oxide film is easily formed. Thereby, for example, even when the film formation target is a microporous porous material, a titanium oxide film can be reliably applied to the surface or in the micropores in the vicinity of the surface.

  In addition, a titanium oxide film forming method in which a film forming solution containing peroxotitanate ions is sequentially applied to a film forming object after a film forming solution containing an alkali is applied. In the case where there is an affinity for the film, it is easy to uniformly apply the alkali to be applied first to the film formation target. A dispersed titanium oxide film can be formed.

  On the other hand, the titanium oxide film forming method for applying a film forming solution containing alkali after the film forming solution containing peroxotitanate ions is applied to the film forming object is When there is an affinity for a film-forming solution containing acid ions, peroxotitanate ions are easily applied uniformly to the object to be formed, and a highly dispersed titanium oxide film is formed by applying alkali thereafter. Can be formed.

  Further, the aqueous solution of titanium salt and hydrogen peroxide may be applied to the film formation target in the form of a mixed solution. In this case, an alkaline aqueous solution to which peroxotitanate ions generated in the mixed solution are subsequently applied. Thus, a titanium oxide film can be formed.

  Moreover, after providing a titanium salt aqueous solution to a film formation target, a hydrogen peroxide solution may be provided, and then an alkaline aqueous solution may be provided. After applying a titanium salt aqueous solution to the film formation target, peroxotitanate ions generated by applying a hydrogen peroxide solution act on an alkali aqueous solution applied thereafter to form a titanium oxide film. Can do.

  Similarly, a hydrogen peroxide solution may be applied to a film formation target, a titanium salt aqueous solution may be applied, and then an alkaline aqueous solution may be applied. Peroxotitanate ions generated by applying a hydrogen peroxide solution to a film formation target and then applying a titanium salt aqueous solution act on an alkaline aqueous solution applied thereafter to form a titanium oxide film. Can do.

  Similarly, a peroxotitanate ion aqueous solution and an alkaline aqueous solution may be simultaneously applied to the film formation target. Simplify the process because two liquids can be applied in one step by simultaneously applying a titanium oxide film forming solution consisting of two liquids, a peroxotitanate aqueous solution and an alkaline aqueous solution, to the film formation target. Can do.

  Similarly, a titanium oxide film-forming solution consisting of three liquids of a titanium salt aqueous solution, a hydrogen peroxide solution, and an alkaline aqueous solution may be simultaneously applied to the film formation target. By simultaneously applying the titanium salt aqueous solution, the hydrogen peroxide solution, and the alkaline aqueous solution to the film formation target, the three liquids can be applied in one step, so that the process can be simplified.

  Similarly, a titanium oxide film-forming solution composed of two liquids in which a mixed solution of a titanium salt aqueous solution and hydrogen peroxide is one liquid and an alkaline solution is the other liquid may be applied simultaneously or sequentially. Also in this case, the application process can be simplified if the application is performed simultaneously.

  Such a titanium oxide film-forming solution can be applied, immersed, or applied by any application method such as spraying, but if applied in the form of a spray, it is more uniform with respect to the film-forming target. In addition, a highly dispersed titanium oxide film can be formed.

  In the case of spraying, each titanium oxide film-forming solution is stored in a chemical solution tank or the like, and the chemical solution is directed toward the film formation target by using an injection device having a plurality of injection ports corresponding to the number of each chemical solution. Can be sprayed. When spraying toward a film formation object at the same time using a double-head gun and an injection device having a plurality of injection ports, the injected chemicals are mixed with each other in the air, and titanium oxide is precipitated in the air However, even if the object to be deposited is a smooth surface or a porous object, it can be formed as long as it has sufficient openings to allow fine particulate titanium oxide to be deposited in the air. A highly dispersed titanium oxide film is formed on the film object.

  When all the chemicals are mixed and stored in advance, titanium oxide is generated in the storage tank. In such a case, when the particulate titanium oxide is sprayed or when the gelled titanium oxide is sprayed, it is difficult to form a highly dispersed titanium oxide film.

  In any case, according to the method for forming a titanium oxide film of the present invention, it is possible to easily form a titanium oxide film on the surface of an object to be formed without requiring a heating step or an ion exchange step. It is possible to produce a titanium oxide coated body in which titanium oxide is highly dispersed on the surface.

  In addition, in the present invention, since peroxotitanate ions are reacted with alkali, titanium oxide is easily highly dispersed as compared with the case of using a titanium oxide aqueous solution or titanium oxide gel containing particulate titanium oxide. be able to. For this reason, the amount of titanium oxide required for film formation can be reduced, and the manufacturing cost can be reduced. The titanium oxide film in which titanium oxide is highly dispersed is efficient because it has a large contact area with the decomposition target, and can exhibit higher photocatalytic ability.

  Further, according to the titanium oxide film formed by the film forming method of the present invention, it is considered that a predetermined substance is adsorbed when it is not irradiated with ultraviolet rays and exhibits a photocatalytic function when irradiated with ultraviolet rays. . For example, if a titanium oxide film formed by the film forming method of the present invention is provided outdoors, nitrogen oxide (NOx), which is one of air pollutants, is adsorbed at night, and sunlight is irradiated in the daytime. Then, it is considered that it functions as a photocatalyst to oxidize and remove nitrogen oxides. That is, according to the present invention, it is possible to impart a function of adsorbing and removing nitrogen oxides in the atmosphere to various materials capable of holding concrete products and alkalis, and can contribute to the purification of the air environment. . In addition, it is considered that the soil component mainly composed of organic substances adhering to the surface of such concrete products can be decomposed by the titanium oxide film.

The peroxotitanate ion aqueous solution used in the present invention may be an aqueous solution containing peroxotitanate ions (chemical formula) derived from peroxotitanate (titanium peroxide: TiO ₃ · nH ₂ O), and the production method Is not particularly limited. For example, a peroxotitanate ion aqueous solution can be easily obtained by mixing a titanium salt aqueous solution such as a titanium sulfate (Ti (SO ₄ ) ₂ ) aqueous solution or a titanium chloride (TiCl ₄ ) aqueous solution with a hydrogen peroxide solution. .

In addition to titanium sulfate and titanium chloride, titanium salts used in such aqueous titanium salt solutions include potassium peroxotitanate (K ₄ TiO ₈ · 6H ₂ O), sodium peroxotitanate (Na ₄ TiO ₈ · 2H ₂ O or Na ₂ O ₂ · TiO ₃ · 3H ₂ O) or the like can be used, but is not particularly limited as long as it is a water-soluble titanium salt that dissolves in water and generates peroxotitanate ions.

In addition, as the alkali used in the present invention, alkali metal hydroxide, alkaline earth metal hydroxide, and the like can be used. For example, sodium hydroxide (NaOH), calcium hydroxide (Ca (OH) ₂ ), Strontium hydroxide (Sr (OH) ₂ ), barium hydroxide (Ba (OH) ₂ ) and the like can be used. Furthermore, ammonia (NH ₃ ) or the like can also be used as the alkali.

  In any case, in the present invention, an alkali and peroxotitanate ions are reacted to form a titanium oxide film, thereby generating titanium oxide in the deep layer portion of the film formation target, A titanium oxide film can be efficiently formed only on the surface (or only on the surface layer portion). That is, since titanium oxide exhibits a photocatalytic function when irradiated with ultraviolet rays, if a titanium oxide film is formed on the surface of a film formation target, a greater effect can be obtained using a small amount of titanium. .

  Furthermore, the alkali may be held on the surface of the film formation target in any manner. For example, the material of the film formation target itself may be formed from an alkali-containing material so that the surface thereof has an alkali. Alternatively, the film formation target may hold a separate alkali-containing material. Thus, the surface may have an alkali. Furthermore, the alkali may be adhered to the surface of the film formation target by applying, spraying, or dipping the alkali-containing liquid. In this case, in order to hold the alkali more uniformly on the surface, it is preferable to form the film formation target from a porous material. This is because if the alkali-containing liquid is sprayed on the porous material, the alkali is supported in the pores of the porous material.

  In the case where the material of the film formation target itself is formed from an alkali-containing material, a hydraulic inorganic material using calcium oxide CaO such as alkaline cement or fly ash as a curing source can be employed as the alkali-containing material. If such an alkali-containing material is used as a film formation target, a surface having alkali can be formed without any special processing. In particular, if a titanium oxide film is formed using powdered fly ash as a film formation target, the organic substance is decomposed and removed by spraying it on soil contaminated with organic substances such as oil and agricultural chemicals. It is thought that you can.

  On the other hand, when a separate alkali-containing material is held on the film formation target, for example, it is held by applying paste-like calcium hydroxide, strontium hydroxide, cement, etc. to the film formation target made of concrete. Just do it. Even in this case, the surface of the film formation target is constituted by the held alkali-containing material, and the surface has alkali.

  Moreover, when making an alkali containing liquid adhere to the surface of a film-forming target object, the method to make it adhere is not limited. For example, an aqueous solution of sodium hydroxide, an aqueous solution of barium hydroxide, or the like can be applied to a film formation target, immersed, or sprayed to adhere. For example, in order to adhere the alkali more uniformly to the film formation target, it is preferable to deposit it by spraying. Moreover, if it adheres by application | coating, it can be made to adhere easily even if it is an existing structure. For example, when adhering to a concrete block or the like at the manufacturing stage, adhesion by dipping is suitable from the viewpoint of production efficiency.

  As the above-mentioned porous substance, any substance having a large number of fine pores can be arbitrarily selected within the range where the effects of the present invention can be achieved. For example, any of concrete, silica gel, alumina, talc, sand, calcium carbonate, calcium nitride, calcium carbide, hydroxyapatite, etc. may be used, and any two or more of these may be used. Also good. However, the porous material is preferably not an organic material. This is because the porous material itself may be decomposed by the photocatalytic function of titanium oxide formed on the surface. If an organic material made of an organic substance is used as a film formation target (base material), for example, the above-described organic material may be held with an inorganic substance as an intermediate layer, and the surface may be formed with the inorganic substance. In this way, a titanium oxide film can be formed on the organic material as the base material, and the risk of the organic material being decomposed by the photocatalytic function of titanium oxide can be reduced.

  In addition, a method for attaching a peroxotitanate ion aqueous solution, a soluble titanium aqueous solution, or a hydrogen peroxide solution to a film formation target is not particularly limited, and the film can be attached by a desired method such as spraying, coating, or dipping. If it adheres by spraying on a film-forming target, it can make it adhere more uniformly and highly dispersed. Moreover, if it adheres by application | coating, it can be made to adhere easily even if it is an existing structure. For example, when adhering to a concrete block or the like at the manufacturing stage, adhesion by dipping is suitable from the viewpoint of production efficiency.

  As described above, the embodiment of the present invention has been described in detail with an example of the method of forming a titanium oxide film, but the specific configuration is not limited to this embodiment.

  For example, since the amorphous titanium dioxide obtained by the present invention precipitates in the form of fine particles, in addition to the use as a film, there is a possibility of using it in a slurry state by utilizing the function as fine particles as it is. A titanium thin film can be provided by mixing the slurry with an appropriate binder or applying it to an object as it is. As the object in this case, the above-described film formation object can be used as it is, but the application to the porous body having fine pores is more in accordance with the above-described film formation method than in the case of using slurry. However, it is as described above that application to the inner surface of the fine hole is easy.

  In addition, the reaction mixture containing titanium oxide obtained by the reaction of the present invention is characterized by functioning as a photocatalyst in the form of the mixture as it is. Thereby, the titanium oxide produced | generated by this invention does not need to isolate | separate and refine and utilize. Of course, it can be used after separation and purification of titanium dioxide when separation and purification are possible, including when all of the side reaction products are soluble, or when separation and purification are easy. Not too long.

  Hereinafter, in order to demonstrate the effect of the present invention, verification is made by examples, but the present invention is not limited to the following examples.

(A) Production of Samples Samples 1 to 36 were produced according to Examples 1 to 5 and Comparative Examples 1 and 2 below. In addition, the density | concentration and spraying amount of each aqueous solution in the samples 1-36 were performed according to Tables 1 thru | or 3.

(A-1) Experimental example 1
Samples 1 to 15 were manufactured by the following steps.
(1) Step of holding an alkali-containing material on a film formation target A paste-like alkali-containing material is applied to the surface of a concrete block (width 10 cm × length 20 cm × thickness 6 cm) as a film formation target (base material). did. As shown in Table 1, as the alkali-containing material, cement was used for Sample 1 to Sample 11, calcium hydroxide was used for Sample 12 and Sample 13, and strontium hydroxide was used for Sample 14 and Sample 15, respectively. .
(2) Step of attaching peroxotitanate ion aqueous solution to film formation target Samples 1 to 9 and Samples 12 to 15 were dried and solidified, and samples 10 and 11 were dried before the cement was dried. The peroxotitanate ion aqueous solution was sprayed. As shown in Table 1, as a peroxotitanate ion aqueous solution, Sample 1 to Sample 4 are a mixed solution of a titanium chloride aqueous solution and a hydrogen peroxide solution, and Sample 5 to Sample 15 are a titanium sulfate aqueous solution and a peroxide. Each mixed solution with hydrogen water was used.
(3) Immersion in deionized water and drying step As shown in Table 1, samples 3, 11, 13, and 15 were immersed in deionized water. In this step, the target sample was immersed in 1.4 l of deionized water for 1 day and then dried. For sample 4, this dipping / drying process was repeated twice.
(A-2) Experimental example 2
Sample 16 and Sample 17 were manufactured by the following steps.
(1) Step of holding alkali-containing material on film formation target A paste-like alkali-containing material was applied to the surface of a concrete block (similar to Experimental Example 1) as a film formation target. As shown in Table 1, cement was used as the alkali-containing material.
(2) The process of making the soluble titanium salt aqueous solution adhere to the surface of the film-forming object It made it adhere by spraying the soluble titanium salt aqueous solution on the surface of the cement hold | maintained at the concrete block. Here, a titanium sulfate aqueous solution was used as the soluble titanium salt aqueous solution.
(3) Step of attaching hydrogen peroxide solution to the film formation target The hydrogen peroxide solution was attached to the surface of the cement to which the titanium sulfate aqueous solution was attached by spraying.
(4) Immersion in deionized water and drying step As shown in Table 1, the sample 17 was immersed in deionized water. In this step, the target sample was immersed in 1.4 l of deionized water for 1 day and then dried.
(A-3) Experimental Example 3
Sample 18 was manufactured by the following process.
(1) A process of attaching a peroxotitanate ion aqueous solution to a film formation target object A 10 g of peroxotitanate ion aqueous solution was applied to an alkali-containing material as a film formation target object by spraying. Here, 25 g of fly ash was used as the alkali-containing material. This fly ash is an alkaline powder and has alkali on its surface. Moreover, as shown in Table 1, a mixed solution of a titanium sulfate aqueous solution and a hydrogen peroxide solution was used as the peroxotitanate ion aqueous solution.

Moreover, it was made to dry after spraying peroxotitanate ion aqueous solution.
(2) Step of depositing fly ash on concrete block Fly ash to which a peroxotitanate ion aqueous solution was adhered was deposited on a concrete block (similar to Experimental Example 1).
(A-4) Experimental Example 4
Samples 19 to 29 were manufactured by the following steps.
(1) The process of adhering alkali to the film formation target The concrete block (similar to Experimental Example 1) as the film formation target was impregnated on the surface by spraying an aqueous alkali solution, thereby attaching the alkali. . As shown in Table 2, a sodium hydroxide aqueous solution was used for samples 19 to 21 and a barium hydroxide aqueous solution was used for samples 22 to 29 as alkaline aqueous solutions.
(2) Step of attaching hydrogen peroxide solution to the film formation target The hydrogen peroxide solution was attached to the surface of the concrete block to which the alkaline aqueous solution was attached by spraying.
(3) Immersion in deionized water and drying step As shown in Table 2, the samples 20, 23, 26, and 29 were immersed in deionized water. In this step, the target sample was immersed in 1.4 l of deionized water for 1 day and then dried. For samples 21, 24, and 27, this dipping / drying process was repeated twice.
(A-5) Experimental Example 5
Samples 32 to 36 were manufactured by the following steps.
(1) Step of mixing titanium-containing hydrogen peroxide solution and alkaline aqueous solution As shown in Table 3, an aqueous solution in which hydrogen peroxide solution is added to a titanium sulfate aqueous solution or a titanium chloride aqueous solution (Ti-H ₂ O ₂ aqueous solution) Sodium hydroxide, barium hydroxide octahydrate, or strontium hydroxide octahydrate was added to form a pale yellow or white precipitate.
(2) Step of removing water-soluble component from precipitate The aqueous solution obtained by mixing as described above was allowed to stand, the supernatant was removed, and 100 ml of water was mixed. Furthermore, this aqueous solution was allowed to stand, the supernatant was removed, and the operation of mixing water was repeated several times. And the water-soluble component was removed by filtering a deposit.
(3) Step of drying precipitate After the obtained precipitate was dried in a desiccator containing silica gel, it was dried in an electric dryer maintained at about 107 ° C. to obtain Samples 32 to 36.
(A-6) Comparative Example 1
As a first comparative example, Sample 30 and Sample 31 were manufactured by a conventional film forming method using a titanium oxide-containing gel.
(1) Preparation process of titanium oxide-containing gel Aqueous ammonia (NH ₄ OH) is added to a mixed aqueous solution of a titanium sulfate aqueous solution and a hydrogen peroxide solution to adjust the pH to 7, whereby a suspension containing a yellow gel substance A liquid was obtained.
(2) Step of attaching the suspension to the film formation target The suspension was attached to a concrete block as the film formation target (similar to Experimental Example 1). (3) Soaking in deionized water and drying step As shown in Table 2, the sample 31 was immersed in deionized water. In this step, the target sample was immersed in 1.4 l of deionized water for 1 day and then dried.
(A-7) Comparative Example 2
As a second comparative example, a paste-like cement was applied to a concrete block (similar to Experimental Example 1), and a sample 32 without a titanium oxide film was manufactured.
(B) Measurement experiment and result of photocatalytic ability and composition of each sample The following experiments were performed on samples 1 to 36 obtained in Experimental Examples 1 to 5 and Comparative Examples 1 and 2.
(B-1) Nitric Oxide Adsorption Rate Measurement (B-1-1) Experimental Method (1) Measurement container (length 10 cm × width 20 cm × thickness 8 cm) in which sample 1 is formed of quartz glass on the upper surface Set. At this time, the sample 1 was disposed so that the surface (the surface on which the titanium oxide film was formed) faced upward.
(2) A gas containing nitrogen monoxide (NO-containing gas) was supplied at 0.5 l / min from one end in the longitudinal direction of the measurement container and discharged from the other end. As the NO-containing gas, a gas having a volume ratio of NO: 4.7 ppm, O ₂ : 10.5 vol%, N2: 89.5 vol% (hereinafter referred to as “first NO-containing gas”), NO: 4 A gas having a volume ratio of 0.7 ppm, N2: 100.0 vol% (hereinafter referred to as “second NO-containing gas”), and a gas having a higher NO concentration than 4.7 ppm were used.
(3) The NO concentration of the gas (exhaust gas) discharged from the other end was measured using a chemiluminescence NO concentration measuring device (TN-7: Yanagimoto Seisakusho). Furthermore, the nitrogen dioxide concentration of the exhaust gas was measured by the detector tube method.
(4) The above (1) to (3) were performed for each of the samples 2 to 32.
(B-1-2) Experimental results (1) During the passage of the first NO gas, the NO concentration of the exhaust gas from the measurement container was the first of the samples 1 to 31 that were supplied to the measurement container. It decreased from the NO concentration (4.7 ppm) of one NO gas.

  Further, nitrogen dioxide was not detected from the exhaust gas (below the lower limit of detection).

Then, even if the second NO-containing gas does not contain oxygen is vented, reduction in NO concentration comparable to the first NO-containing gas is confirmed, and, O ₂ concentration did not decrease.

  Furthermore, in the case of ventilating a gas having a higher NO concentration than 4.7 ppm, the rate of decrease in the NO concentration increased.

On the other hand, in the sample 32, the NO concentration hardly decreased.
(2) The NO adsorption rate was obtained from the following formula from the decrease rate of the NO concentration. This NO adsorption rate corresponds to the NO decrease rate when each sample is not irradiated with ultraviolet rays.

NO adsorption rate (μmol / h) = aeration gas flow rate (l · N / h) × (air supply gas NO concentration−exhaust gas NO concentration) (ppm) /22.4 (l · N / mol)
The results obtained are shown in Tables 1 and 2.
(3) Further, from the experimental results of Samples 1 to 3 and Samples 5 to 9, the relationship between H ₂ O ₂ / Ti (molar ratio, the same applies hereinafter) of the sprayed peroxotitanate ion aqueous solution and the NO adsorption rate is illustrated. It was shown in 1.
(4) From the experimental results of Samples 6, 12, 14, 19, and 22, NO adsorption rates compared for each type of alkali are shown in FIG.
(5) Based on the experimental results of samples 22, 23, 25, 26, 28, and 29, Ba (OH) ₂ / Ti (molar ratio, the same applies hereinafter) and NO adsorption in sprayed barium hydroxide and peroxotitanate aqueous solutions The relationship with speed is shown in FIG.
(B-2) Nitric Oxide Photooxidation Rate Measurement (B-2-1) Experimental Method (1) Sample 1 was measured using a measuring vessel having an upper surface made of quartz glass (length 10 cm × width 20 cm × thickness 8 cm). ). At this time, the sample 1 was disposed so that the surface (the surface on which the titanium oxide film was formed) faced upward.
(2) The first NO-containing gas was supplied at 0.5 l / min from one end in the longitudinal direction of the measurement container and discharged from the other end. Furthermore, ultraviolet rays were irradiated at 0.6 W / cm ² from the upper surface made of quartz glass while venting the first NO-containing gas in this way.
(3) The NO concentration of exhaust gas was measured using a chemiluminescence NO concentration measuring device (TN-7: Yanagimoto Seisakusho). Furthermore, the nitrogen dioxide concentration of the exhaust gas was measured by the detector tube method.
(4) The above (1) to (3) were performed for each of the samples 2 to 31.
(B-2-2) Experimental results (1) When the irradiation with ultraviolet rays was started, the NO concentration began to decrease, and after a certain period of time, the NO concentration in the exhaust gas became constant. The NO photooxidation rate was determined by the following equation using the NO reduction rate when the steady state was obtained as described above, and the results are shown in Tables 1 and 2.

NO photooxidation rate (μmol / h) = aeration gas flow rate (l · N / h) × (air supply gas NO concentration−exhaust gas NO concentration) (ppm) /22.4 (l · N / mol)
(2) From the experimental results of Samples 1 to 3 and Samples 5 to 9, the relationship between the H ₂ O ₂ / Ti of the sprayed peroxotitanate ion aqueous solution and the NO light adsorption rate is shown in FIG.
(3) Further, from the experimental results of Samples 6, 12, 14, 19, and 22, the NO photooxidation rate depending on the type of alkali is shown in FIG.
(4) From the experimental results of samples 22, 23, 25, 26, 28, and 29, the relationship between Ba (OH) ₂ / Ti and NO photooxidation rate in sprayed barium hydroxide and aqueous peroxotitanate ions is shown. This is shown in FIG.
(B-3) Identification of photocatalytic active component (B-3-1) Experimental method (1) X-ray diffraction measurement was performed for each of samples 32-36.
(2) Each of the samples 32-36 was subjected to composition analysis by X-ray photoelectron spectroscopy (X-ray photoelectron spectrometer 5000 type: ULVAC-PHI Co., Ltd.).
(B-3-2) Experimental results (1) The X-ray diffraction patterns of Samples 32-36 are shown in FIG.
(2) Table 4 shows the measurement results of X-ray photoelectron spectroscopy.

(C) Consideration (C-1) NO adsorption property and NO photo-oxidation rate of titanium oxide film For all of Samples 1 to 31, the NO concentration of the exhaust gas from the measurement vessel is the gas sent to the measurement vessel NO concentration (4.7 ppm).

It was confirmed that nitrogen dioxide was not detected from the exhaust gas, and that the NO concentration decreased as much as the first NO-containing gas even when the second NO-containing gas not containing oxygen was vented. In addition, since the O ₂ concentration did not decrease, it was confirmed that the decrease in the NO concentration was not based on the conversion from NO to NO ₂ .

  In addition, when the gas having a higher NO concentration than 4.7 ppm was vented, the rate of decrease in the NO concentration increased. Thereby, it is thought that the decrease in NO concentration is due to adsorption of NO by the concrete blocks (sample 1 to sample 31) having a titanium oxide film. Furthermore, in the sample 32 which was only coated with cement and not provided with a titanium oxide film, the NO concentration was hardly lowered. Therefore, NO adsorption is considered to be related to the titanium oxide film.

Moreover, although the NO adsorption performance and the NO photo-oxidation performance were confirmed also in the sample 30 and the sample 31, the values thereof are lower than those of the samples 5, 16, 17, 20, 21, 25, 29, and the like. ing. From this, it was found that the titanium oxide film formed based on Experimental Examples 1 to 4 of the present invention can disperse titanium oxide more highly than the titanium oxide deposited as a gel. This is because, according to the method for forming a titanium oxide film of the present invention, an aqueous solution in which ionic titanium (peroxotitanate ion) is dissolved is used, so that a gel containing solid titanium oxide is attached. It is considered that titanium oxide can be highly dispersed.
(C-2) H ₂ O ₂ / Ti dependence of NO adsorption rate As shown in FIG. 1, when titanium sulfate is used as the titanium salt, H ₂ O ₂ / Ti is about 0.1 to 1. The NO adsorption rate greatly increased when H ₂ O ₂ / Ti was greater than 1. On the other hand, when titanium chloride was used as the titanium salt, the NO adsorption rate was substantially constant when H ₂ O ₂ / Ti was in the range of 0.1 to ₂ . Samples 3 and 7 immersed in deionized water for one day and dried were samples 1 and 6 having the same H ₂ O ₂ / Ti (H ₂ O ₂ / Ti = 1) and not immersed in deionized water. Higher adsorption rate.
(C-3) NO adsorption rate based on alkali difference As shown in FIG. 3, the sample 12 using calcium hydroxide as the alkali and the sample 14 using strontium hydroxide showed a high NO adsorption rate. In the samples 13 and 15 in which these are immersed in water, the NO adsorption rate is greatly reduced.

According to the results of Samples 19 and 22 using barium hydroxide or sodium hydroxide as the alkali, it was not possible to confirm a great difference from the NO adsorption rate of Samples 20 and 23 in which these were immersed in water.
(C-4) NO photo-oxidation rate based on alkali difference As shown in FIG. 4, the NO photo-oxidation rate is the sample 12, which is not immersed in water, except for the samples 6 and 7 using cement as an alkali. Compared with 14, 19, and 22, Samples 13, 15, 20, and 23 immersed in water showed the same or higher values. From this, it is considered that when an alkali other than cement is used, there is no change in the characteristics that the NO photooxidation rate is remarkably reduced at least by being immersed in water.
(C-5) Dependence of NO photo-oxidation rate on H ₂ O ₂ / Ti As shown in FIG. 2, when titanium chloride is used as the soluble titanium salt, regardless of the value of H ₂ O ₂ / Ti The NO photooxidation rate became substantially constant. On the other hand, in the case of using titanium sulfate as a soluble titanium salt, the increase in H ₂ O ₂ ratio (i.e., H ₂ O ₂ / increase of Ti) NO photooxidation rate due to increases, H ₂ O ₂ / Ti When the value was about 2, the change was minute and the NO photooxidation rate was substantially constant. Samples 3 and 7, which were dipped in deionized water for one day and dried, had the same H ₂ O ₂ / Ti value (H ₂ O ₂ / Ti = 1) and were not immersed in deionized water. 6, the NO adsorption rate was lower, but the NO resolution remained.

The results of such Figure _2, H 2 O 2 / Ti during the formation of the titanium oxide film is preferably used to be _{0.1 ≦ H 2 O 2 / Ti} , a smaller amount of titanium efficiency In order to adsorb NO specifically, it is considered that 1.0 ≦ H ₂ O ₂ /Ti≦2.0 is preferable.

Further, as shown in Table 1, it was found that Samples 16 and 17 also showed a high NO photooxidation rate (4.02 μmol / h). That is, it is understood that a titanium oxide film showing a high NO photooxidation rate can be formed by a film forming method in which a titanium sulfate aqueous solution is sprayed on a concrete block holding cement as an alkali-containing material and then hydrogen peroxide water is sprayed. It was. Moreover, the sample 17 that had been dipped in 1.4 l of deionized water for 1 day and dried also showed the same high NO photooxidation rate (4.02 μmol / h). It is considered that a titanium oxide film that is difficult to be detached from an object can be formed.
(C-6) Relationship between NO adsorption rate and NO photo-oxidation rate and alkali / Ti (molar ratio, the same shall apply hereinafter) As shown in FIG. 5, the NO adsorption rate depends on the value of Ba (OH) ₂ / Ti. The value was almost constant without much dependence.

Further, the NO photooxidation rate tends to increase as Ba (OH) ₂ / Ti increases in the range of 0.25 ≦ Ba (OH) ₂ / Ti <1, and Ba (OH) Near ₂ / Ti = 1, it was substantially constant.

From these results, when Ba (OH) ₂ is used as at least an alkali, the molar ratio is 0.25 ≦ Ba (OH) ₂ / Ti ≦ 1, preferably Ba (OH) ₂ / Ti≈1. Thus, it is considered good to determine the value of Ba (OH) ₂ / Ti.
(C-7) Crystal Structure of Photocatalytically Active Component Referring to FIG. 7, in the Ti (SO ₄ ) ₂ —H ₂ O ₂ —NaOH system, only a wide peak (broad peak) appears, so that it is amorphous. It is thought that the quality component was generated.

In the TiCl ₄ —H ₂ O ₂ —Ca (OH) ₂ system, TiCl ₄ —H ₂ O ₂ —Sr (OH) ₂ system, and TiCl ₄ —H ₂ O ₂ —Ba (OH) ₂ system, A diffraction peak derived from the salt (CaCO ₃ , SrCO ₃ , BaCO ₃ ) was detected. Furthermore, a broad peak derived from an amorphous substance was also detected. These detected carbonates are presumed to have been produced by the absorption of CO ₂ present in the air by the alkaline aqueous solution during the sample production process. These carbonates are considered to remain in the precipitate because of their poor water solubility. Since this carbonate is sparingly water-soluble, it does not easily elute even when it comes into contact with water, and it can be considered that it can function as a binder that retains amorphous titanium dioxide and prevents elution. Therefore, when the titanium oxide film is formed by the titanium oxide film forming method of the present invention, Ca (OH) ₂ , Sr (OH) ₂ , or Ba (OH) ₂ is used as the alkali, and this alkali remains. If the peroxotitanate ion aqueous solution is attached, the carbonate is formed with time by contact with air, and the elution of the amorphous titanium dioxide can be prevented to improve the durability of the titanium oxide film. It is considered possible.

Further, TiCl ₄ —H ₂ O ₂ —Ca (OH) ₂ system, TiCl ₄ —H ₂ O ₂ —Sr (OH) ₂ system, and TiCl ₄ —H ₂ O ₂ —Ba using titanium chloride as a titanium salt. In the (OH) ₂ system, it is considered that sodium chloride, calcium chloride or barium chloride is produced, but these are not detected from the precipitate. This is because sodium chloride, calcium chloride or barium chloride is water-soluble. Therefore, when a titanium oxide film is formed by the titanium oxide film forming method of the present invention, titanium chloride is used as the titanium salt, and calcium hydroxide, strontium hydroxide, and barium hydroxide are used as the alkaline earth metal hydroxide. If any one of these is used, chlorine (chlorine compound) can be easily removed only by washing with water.

  On the other hand, according to the method for forming a titanium oxide film of the present invention in which the titanium salt is titanium sulfate and the alkaline earth metal hydroxide is any one of calcium hydroxide, strontium hydroxide, and barium hydroxide, When producing titanium oxide, calcium sulfate, strontium sulfate, or barium sulfate is produced. And since this calcium sulfate, strontium sulfate, or barium sulfate functions as a binder of titanium oxide (titanium dioxide) without substantially reducing the photocatalytic ability of the titanium oxide film, it is difficult for titanium oxide to elute due to rain, etc. A highly durable titanium oxide film can be formed.

In addition, in the Ti (SO ₄ ) ₂ —H ₂ O ₂ —Ba (OH) ₂ system, a broad diffraction peak is detected in addition to a clear diffraction peak derived from poorly water-soluble barium sulfate (Ba (SO ₄ ) ₂ ). It was done. A broad peak appears in common in the X-ray diffraction patterns of these precipitates. From this, it is presumed that the titanium oxide film formed according to the present invention is a photocatalytic component in which the amorphous component shows activity in NO photooxidation.
When (C-8) Referring to identify tables 4 photocatalytic active _{component, Ti (SO 4) 2 -H} 2 O 2 -NaOH _{system, TiCl 4 -H 2 O 2 -Ca} (OH) 2 system, TiCl ₄ -H _{In the 2} O ₂ —Sr (OH) ₂ system and the TiCl ₄ —H ₂ O ₂ —Ba (OH) ₂ system, each precipitate contains titanium, oxygen, alkali or alkaline earth metal, , Found to contain carbon. Here, assuming that the alkali of each of these precipitates is all present as carbonate (MCO ₃ ), the atomic ratio between the remaining oxygen and titanium was found to be almost 2 (Ti: O≈ 1: 2). From this, it is estimated that titanium exists as titanium dioxide (TiO ₂ ).

On the other hand, in the Ti (SO ₄ ) ₂ —H ₂ O ₂ —Ba (OH) ₂ system, it was found that the precipitate contained titanium, oxygen, barium, and sulfur. Assuming that all the barium in the precipitate exists as barium sulfate (BaSO ₄ ), the atomic ratio between the remaining oxygen and titanium was determined to be approximately 2.5 (Ti: O≈2: 5). From this, it is estimated that titanium exists as titanium dioxide (TiO ₂ ).

  Considering together the result of the composition analysis and the result of the X-ray diffraction analysis described above, in the method for forming a titanium oxide film of the present invention, amorphous titanium dioxide (amorphous titanium dioxide) is generated. It can be inferred that this is a photocatalytic component active in NO photooxidation. That is, according to the method for forming a titanium oxide film of the present invention, a titanium oxide film containing amorphous titanium dioxide as a photocatalytic component can be formed. In addition, carbonates and barium sulfate coexist in these precipitates, but it is considered that the photocatalytic activity of amorphous titanium dioxide is remarkably inhibited by these coexisting substances from the measurement result of the photooxidation rate of NO. I can't. Since these crystalline coexisting substances are hardly water-soluble, they are not easily eluted even when they come into contact with water, and are considered to function as a binder that retains amorphous titanium dioxide and prevents elution. Therefore, according to the method for forming a titanium oxide film of the present invention in which the titanium salt is titanium sulfate and the alkaline earth metal hydroxide is any one of calcium hydroxide, strontium hydroxide, and barium hydroxide, When producing titanium oxide, calcium sulfate, strontium sulfate, or barium sulfate is produced. And since this calcium sulfate, strontium sulfate, or barium sulfate functions as a binder of titanium oxide (titanium dioxide) without substantially reducing the photocatalytic ability of the titanium oxide film, it is difficult for titanium oxide to elute due to rain, etc. A highly durable titanium oxide film can be formed.

Example 2 below is an example for demonstrating that a titanium oxide film having a photocatalytic function is formed even when the timing of applying alkali is changed, and the present invention includes the following examples. It is not limited.
(Experimental examples 201 to 204)
Spray the surface of a commercially available concrete block (width 10 cm x length 20 cm x thickness 6 cm) with a mixture of Ti (SO ₄ ) ₂ (0.60% as Ti) and H ₂ O ₂ (0.43%). After ( ² g-solution / 200 cm ² ), an aqueous solution of sodium hydroxide was sprayed ( ² g-hydroxide / 200 cm ² ) (Test 201).

Similar to Test 201, Ti (SO ₄ ) ₂ (0.60% as Ti) and H ₂ O ₂ (0.43%) were placed on the surface of a commercially available concrete block (width 10 cm × length 20 cm × thickness 6 cm). After spraying ( ² g-solution / 200 cm ² ), an aqueous solution of barium hydroxide was sprayed ( ² g-hydroxide / 200 cm ² ) (Test 203).
After placing the titanium oxide film on the concrete block surface in a container (length 10 cm × width 20 cm × thickness 8 cm) whose top surface was opened, the top surface was covered with quartz glass. A gas containing NO (0.95 ppm, O ₂ : 10.5%, N ₂ : 89.5%) is vented from one end in the longitudinal direction of this container (1 L-N / min: vented NO) (Concentration = 4.7 ppm), the gas was taken out from the other end in the longitudinal direction of the container, and the NO concentration was measured by a chemiluminescence NO concentration measuring device.
As a result, the NO concentration at the outlet of the container was lower than the NO concentration at the inlet of the container (NO: 0.95 ppm). This is considered to be due to NO adsorption, and the NO adsorption rate was calculated by the following equation. Are shown in Table 5.

  NO adsorption rate (μmol / h) = gas flow rate (l−N / h) × (container inlet NO concentration−container outlet NO concentration) (ppm) /22.4 (l−N / mol)

After spraying an aqueous solution in which Ti (SO ₄ ) ₂ and H ₂ O ₂ are mixed, the sample sprayed with an aqueous solution of sodium hydroxide (Test 201) or the sample sprayed with an aqueous solution of barium hydroxide (Test 203) is 0 respectively. .18 and 0.16 μmol / h 2 of NO adsorption rates were shown, indicating NO adsorption performance.

Next, while venting a gas containing NO to the container, ultraviolet light was irradiated from above the quartz glass of the container (0.6 W / cm ² ), and the NO concentration at the container outlet was measured. With the UV irradiation, the NO concentration began to decrease, and the NO concentration became a constant value. Based on the decrease rate of the NO concentration at this time, the NO photooxidation rate was obtained by the following formula, and the results are shown in Table 5 together.

NO photooxidation rate (μmol / h) = gas flow rate (1-N / h) × (container inlet NO concentration−container outlet NO concentration) (ppm) /22.4 (l-N / mol)
After spraying an aqueous solution containing Ti (SO ₄ ) ₂ and H ₂ O ₂ on the surface of the concrete block, the samples sprayed with an aqueous solution of sodium hydroxide (test 201) or barium hydroxide (test 203) were each 0.00. NO photooxidation rates of 83 and 0.98 μmol / h were shown, indicating NO photooxidation performance.
Furthermore, the block on which the titanium oxide film produced as described above is formed is immersed in water (deionized water, 1.4 l) for a day and then dried, and the NO adsorption rate and the NO photooxidation rate are set in the same manner as described above. Determined (tests 202 and 204).

  The NO adsorption rate of the concrete block of test 202 or test 204 is 0.08 and 0.08 μmol / h, respectively, and the NO photooxidation rate is 0.59 and 0.66 μmol / h, respectively. It was found that NO adsorption performance and NO photooxidation performance remained, although both were lower than before water immersion.

Such a decrease in the NO adsorption rate and the NO photo-oxidation rate is presumed to be because a part of the titanium oxide held on the surface of the concrete block during water immersion dropped off.
(Experimental examples 205-208)
Spraying an aqueous solution in which Ti (SO ₄ ) ₂ (0.60% as Ti) and H ₂ O ₂ (0.43%) are mixed on the surface of a commercially available concrete block (width 10 cm × length 20 cm × thickness 6 cm) And spraying with an aqueous solution of sodium hydroxide (NaOH) were carried out by simultaneous spraying under the conditions shown in Table 5 (application 205).
Further, spraying of an aqueous solution in which Ti (SO ₄ ) ₂ (0.60% as Ti) and H ₂ O ₂ (0.43%) are mixed and spraying of an aqueous solution of barium hydroxide (Ba (OH) ₂ ) are shown. (Test 207).
Thus, about the block in which the titanium oxide membrane | film | coat was formed, water immersion was performed similarly to said Experimental example 201-204 (test 206,208).

  Table 5 shows the results of measuring the NO adsorption rate and the NO photooxidation rate before water immersion (tests 205 and 207) and after water immersion (tests 206 and 208).

Samples before water immersion (tests 205 and 207) had NO adsorption rates of 0.19 and 0.16 μmol / h, respectively, and NO photooxidation rates of 1.18 and 0.90 μmol / h, respectively. And NO photooxidation performance. Furthermore, these samples were immersed in water (deionized water) for a day and then dried (tests 206 and 208) had NO adsorption rates of 0.05 and 0.06 μmol / h, respectively, and the NO photooxidation rate was They were 0.23 and 0.35 μmol / h, respectively, and it was found that both NO adsorption performance and NO photooxidation performance remained.
Compared to the decrease in the NO adsorption rate and the NO photooxidation rate after immersion in water in Experimental Examples 201 to 204, the decrease in the NO adsorption rate and the NO photooxidation rate after immersion in water in this case is large. This is presumably because a part of the titanium oxide held on the surface of the concrete block when immersed in water was largely removed.
From the above results, the concrete of the titanium oxide film that is produced when the peroxy titanate aqueous solution and the alkaline aqueous solution are sprayed simultaneously after spraying the peroxy titanate aqueous solution on the surface of the concrete block as compared with the case of spraying the alkaline aqueous solution. It is considered that the adhesion (fixing force) to the block surface is lowered. This is because when the peroxytitanic acid aqueous solution and the alkaline aqueous solution are sprayed at the same time, the proportion of titanium oxide generated outside the pores on the surface increases, and the titanium oxide generated outside the pores is a film-like solid. This is probably because it cannot enter the pores and easily drops off when immersed in water.
On the other hand, when spraying an aqueous solution of peroxytitanic acid and then spraying an aqueous alkaline solution, the aqueous solution of peroxytitanic acid penetrates into the pores of the surface and then the aqueous alkaline solution is supplied. It is considered that the film is formed at a higher rate in the pores and is less likely to fall off when immersed in water.

Further, the invention according to claim 3 is characterized in that a titanium oxide film is formed by allowing peroxotitanate ions, which may be derived from a reaction product of a titanium salt aqueous solution and hydrogen peroxide, to act in the presence of an alkali. It is a method (except for a method of forming a titanium oxide film in which a titanium oxide film is formed by attaching a peroxotitanate ion aqueous solution to a film formation target having an alkali on the surface).

Claims (31)

  A method for producing titanium oxide, comprising reacting peroxotitanate ions, which may be derived from a reaction product of a titanium salt aqueous solution and hydrogen peroxide, in the presence of an alkali.   A photocatalytically active mixture containing titanium oxide, wherein peroxotitanate ions, which may be derived from a reaction product of a titanium salt aqueous solution and hydrogen peroxide, are allowed to act in the presence of an alkali.   A method for forming a titanium oxide film, comprising allowing peroxotitanate ions, which may be derived from a reaction product of a titanium salt aqueous solution and hydrogen peroxide, to act in the presence of an alkali.   The peroxotitanate ion is (1) provided to the film formation target in the form of an aqueous solution, or (2) is derived from a reaction product of a titanium salt aqueous solution and hydrogen peroxide, and the titanium salt aqueous solution and The method for forming a titanium oxide film according to claim 3, wherein the film is applied to the object to be formed in the form of hydrogen peroxide.   The method for forming a titanium oxide film according to claim 4, wherein the alkali is derived from a film formation target and / or applied to the film formation target.   6. The method for forming a titanium oxide film according to claim 5, wherein the alkali and peroxotitanate ions are simultaneously or sequentially applied to the film formation target.   The method for forming a titanium oxide film according to claim 6, wherein an aqueous alkaline solution is applied after a peroxotitanate ion aqueous solution is applied to the film formation target.   The method of forming a titanium oxide film according to claim 6, wherein an alkaline aqueous solution is applied after applying a mixed solution of a titanium salt aqueous solution and hydrogen peroxide to the film formation target.   The method for forming a titanium oxide film according to claim 6, wherein after the titanium salt aqueous solution is applied to the film formation target, a hydrogen peroxide solution is applied, and then an alkaline aqueous solution is applied.   The method for forming a titanium oxide film according to claim 6, wherein after the hydrogen peroxide solution is applied to the film formation target, a titanium salt aqueous solution is applied, and then an alkaline aqueous solution is applied.   The method for forming a titanium oxide film according to claim 6, wherein a peroxotitanate ion aqueous solution and an alkaline aqueous solution are simultaneously applied to the film formation target.   The method for forming a titanium oxide film according to claim 6, wherein a titanium salt aqueous solution, a hydrogen peroxide solution, and an alkaline aqueous solution are simultaneously applied to the film formation target.   4. The method for forming a titanium oxide film according to claim 3, wherein a titanium oxide film is formed by adhering a peroxotitanate ion aqueous solution to a film formation target having an alkali on the surface.   14. The method for forming a titanium oxide film according to claim 13, wherein the peroxotitanate ion aqueous solution is a mixed aqueous solution of a titanium salt aqueous solution and a hydrogen peroxide solution.   4. The titanium oxide film according to claim 3, wherein a titanium oxide film is formed by attaching a titanium salt aqueous solution to a film formation target having an alkali on the surface and then attaching hydrogen peroxide. Membrane method.   The method for forming a titanium oxide film according to claim 14 or 15, wherein the titanium salt is titanium sulfate or titanium chloride.   The method for forming a titanium oxide film according to claim 13, wherein the object to be formed is made of an alkali-containing material.   The method for forming a titanium oxide film according to any one of claims 13 to 16, wherein the surface is formed of an alkali-containing material held by the object to be formed.   The method for forming a titanium oxide film according to claim 17 or 18, wherein the alkali-containing material is cement or fly ash.   The method for forming a titanium oxide film according to claim 3, wherein the object to be formed is made of a porous material.   17. The titanium oxide film according to claim 13, wherein the surface is made of a porous material, and the alkali is supported on the surface formed of the porous material. Membrane method.   The film formation of a titanium oxide film according to claim 20 or 21, wherein the porous material is any one of concrete, silica gel, alumina, talc, calcium carbonate, or sand, or a mixture of two or more. Method.   23. The titanium oxide film according to claim 3, wherein the alkali is any one of an alkali metal hydroxide, an alkaline earth metal hydroxide, and ammonia. Membrane method.   24. The titanium oxide film according to claim 23, wherein the titanium salt is titanium sulfate, and the alkaline earth metal hydroxide is any one of calcium hydroxide, strontium hydroxide, and barium hydroxide. The film forming method.   24. The titanium oxide film according to claim 23, wherein the titanium salt is titanium chloride, and the alkaline earth metal hydroxide is any one of calcium hydroxide, strontium hydroxide, and barium hydroxide. The film forming method.   The titanium oxide film-forming solution containing peroxotitanate ions, which may be derived from a reaction product of the titanium salt aqueous solution and hydrogen peroxide, is applied to the film-forming object in the form of a spray. The method for forming a titanium oxide film according to claim 3.   A method for producing a titanium oxide coated body, wherein the method for forming a titanium oxide film according to any one of claims 3 to 26 is used.   A titanium oxide coated body obtained by the titanium oxide film forming method according to any one of claims 3 to 26 or the titanium oxide coated body manufacturing method according to claim 27.   A solution for forming a titanium oxide film comprising two solutions of a peroxotitanate ion aqueous solution and an alkaline aqueous solution.   A solution for forming a titanium oxide film comprising two solutions of a mixed solution of an aqueous solution of titanium salt and hydrogen peroxide and an alkaline solution.   A titanium oxide film-forming solution comprising three liquids of an aqueous titanium salt solution, a hydrogen peroxide solution, and an alkaline solution.

Images