MXPA00005147A - Photocatalyst composition, substance containing photocatalyst, and material functioning as photocatalyst and process for producing the same - Google Patents

Abstract

When a nitrogen oxide (nitrogen monoxide) is contacted with or approaches titanium dioxide functioning as a photocatalyst and compounded with either an amphoteric metal oxide having basic sites (alumina, etc.) or a basic metal oxide (barium oxide, strontium oxide, etc.), the nitrogen monoxide is oxidized into nitrogen dioxide (gas) with•OH which is an active oxygen species generated by the titanium dioxide upon irradiation with light. Since alumina is an amphoteric metal oxide and barium oxide and strontium oxide are basic metal oxides, oxygen atoms of these metal oxides function as basic sites for acidic gases. Consequently, the nitrogen dioxide, which is an acidic gas because of its molecular structure, is attracted by and chemically bonded to these oxygen atoms. Thus, the nitrogen dioxide is held on the metal oxide at positions close to the titanium dioxide, serving as a photocatalyst.

Description

PHOTOCATALIZING FORMULATION, MATERIAL THAT CONTAINS PHOTOCATALYZER AND PHOTOCATALYTICALLY ACTIVABLE MATERIAL AND PROCESS FOR YOUR PRODUCTION TECHNICAL FIELD The present invention relates to a photocatalytic formulation containing a photocatalyst that can function as a catalyst upon exposure to light, and a photocatalytically activatable material using the photocatalyst formulation and a process for producing the same. PREVIOUS TECHNIQUE This type of photocatalyst finds wide applications because the energy used in catalytic reactions is light energy, such as sunlight that is inexhaustible. For example, titanium dioxide (Ti02), a type of photocatalyst, particularly titanium oxide in an anatase crystal form, produces excitation electrons and positive holes or holes upon exposure to light energy (ultraviolet light) and excitation electrons. and the positive orifices produce active oxygen species such as 02", O", and OH (where it represents an unpaired electron, and means that the species accompanied with 'is a radial species), in the presence of oxygen and water in the catalyst surface. There are applications that use radical properties of active oxygen species have been proposed, such as air purification applications, where nitrogen oxides (NOx) in the air, are oxidized with the active oxygen species and consequently converted to a harmless reaction product (nitric acid) and degradation of bacteria through the oxidation of organic matter, that is, the so-called antimicrobial applications. In the course of oxidation of nitrogen oxides with active oxygen species, nitrogen dioxide (N02) is produced as an intermediate that is further oxidized and finally converted to nitric acid. As a result of the production of nitric acid, nitrogen oxides in the air are reduced and the air is purified. For this reason, the co-presence of the active oxygen species and the oxides of nitrogen or nitrogen dioxide, are indispensable to improve the reduction in percent of nitrogen oxide. However, nitrogen dioxide is a chemically stable compound in relative form (gas), the nitrogen dioxide produced is the remainder of the reaction system. This reduces the efficiency of oxidation with the active oxygen species, resulting in less reduction in percent of the nitrogen oxides. The use of porous adsorbents, such as activated carbon, is considered effective to prevent nitrogen dioxide from remaining in the reaction system. As is notable from the following description, this method is not always effective. Specifically, once it has been left, when nitrogen dioxide is adsorbed in the above adsorbent, nitrogen dioxide often remains after adsorption into the pores of the adsorbent without being released. For this reason, in some cases, the nitrogen dioxide adsorbed is placed outside the oxidation system with the active oxygen species and is not subjected to the oxidation reaction and therefore can not be converted to nitric acid as a final product. In this way, the nitrogen oxides do not finally convert to nitric acid. This inhibits the reduction of nitrogen oxides. In this case, it will be noted that the nitrogen dioxide adsorbed on the adsorbent in a region where nitrogen dioxide may be present together with the active oxygen species, and is in the reaction system, that is, in a region close to the photocatalyst, it is oxidized to produce nitric acid. Since, however, the region near the photocatalyst occupies only a small proportion of the entire region of material adsorption (including pores) in the adsorbent, it can be said that the proportion of nitrogen dioxide, which can not be oxidized in nitric acid, is elevated That is, the adsorbent simply adsorbs and retains the nitrogen dioxide and the percentage reduction of the nitrogen oxides by conversion to nitric acid does not appear to be satisfactory. The present invention has been made with the aim of solving the above problems, and an object of the present invention is further to improve the efficiency of a catalytic reaction, wherein a photocatalyst participates, or to improve the percentage reduction of the reagent applied to the catalytic reaction through the conversion of the reactants into the final product. Another objective of the present invention is to supplement the function of a photocatalyst. DESCRIPTION OF THE INVENTION In order to achieve the above objectives, according to one aspect of the present invention, there is provided a photocatalytic formulation comprising: a photocatalyst that functions as a catalyst upon exposure to light; and another compound, characterized in that, when a reagent is applied to the catalytic reaction, in which the photocatalyst participates, it is catalytically reacted and chemically converted to a final product specified by the reagent structure and the catalytic reaction, the other compound functions in the co-presence of the photocatalyst to improve the conversion of the reagent in the final product. According to the photocatalytic formulation having the above constitution according to the first aspect of the present invention, the conversion of the reagent into the final product can be improved and therefore the percentage reduction of the reagent can be improved as well. In the photocatalytic formulation having the above constitution according to the first aspect of the present invention, the following preferred embodiments may be adopted. According to a first preferred embodiment of the present invention, the other compound is the reagent, or a compound that chemically binds with an intermediate produced before the reagent is catalytically reacted and converts the final product. In this first embodiment, the reagent or intermediate is maintained in such a state that it is chemically bound to the other compound that has been formulated together with the photocatalyst. • This other compound with the reagent or the intermediate there held or retained does not take any porous structure. Therefore, the reagent or the intermediate is not placed outside the system of the catalytic reaction, where the photocatalyst participates, that is, in a distant region of the photocatalyst, and on the contrary the reagent or the intermediate is placed inside the system of catalytic reaction, adjacent to the photocatalyst that has been formulated together with the other compound. In addition, since the reagent or intermediate is chemically linked to the other compound, the reagent or intermediate can safely be placed within the catalytic reaction system. As a result, the photocatalyst formulation according to the first preferred embodiment can ensure the opportunity because the reagent is applied to the catalytic reaction and the opportunity for the intermediate to be applied to this catalytic reaction. This can also improve the efficiency of the catalytic reaction. The improved efficiency of the catalytic reaction can improve the conversion of the reactant to the final product and therefore can improve the percentage reduction of the reagent. According to a second preferred embodiment, upon exposure to applied light energy, the photocatalyst produces excitation electrons and positive orifices that produce a species of active oxygen in the presence of oxygen and water on the surface of the catalyst.

In accordance with this second preferred embodiment of the present invention, the reagent or intermediate is placed within the system of a catalytic reaction based on active oxygen species produced by the photocatalyst. This ensures the opportunity that the reagent is applied to the catalytic reaction or the opportunity that the intermediate is additionally applied to the catalytic reaction. This allows the catalytic reaction to proceed more efficiently. Therefore, the percentage reduction of the reagent can be improved. In this case, examples of photocatalysts usable here include titanium dioxide (Ti02), zinc oxide (ZnO), vanadium oxide (V205) and tungsten oxide (03). These photocatalysts are not restricted by their crystalline form and can be in any crystalline form, for example an anatase, rutile or brookite form, with the anatase titanium dioxide preferred from the point of view of good availability and the like. Regarding reagents applicable to the catalytic reaction based on the active oxygen species, intermediates produced from the reactants, and final products produced from the intermediates, for example, when the reagent is nitrogen oxide, the product intermediate final are nitrogen dioxide and nitric acid, respectively; when the reactant comprises sulfur oxides, the intermediate and the final product are sulfur dioxide and sulfuric acid or sulfurous acid, respectively; and when the reactant is carbon monoxide, the intermediate and the final product are carbon dioxide and carbonic acid, respectively. In addition, ammonia can also be mentioned as an example of the reagent. In this case, the intermediate of the final product is nitrogen monoxide or nitrogen dioxide that are produced from ammonia and nitric acid, respectively. According to a third preferred embodiment of the present invention, the other compound is the reagent applied to the catalytic reaction, based on the active oxygen species, or at least one metal oxide selected from amphoteric metal oxides, metal oxides basic, and oxides of acidic metals that are chemically linked with the intermediary. According to this third preferred embodiment, when placing the reagent or the intermediate within the system of the catalytic reaction, based on the species of active oxygen produced by the photocatalyst, when the reagent or the intermediate is acidic, the so-called "point base "can be formed using a specific atom derived from the structure or atomic arrangement of a basic metal oxide. At this base point, the basic metal oxide can be chemically bonded securely with the reagent or the intermediate. When the reagent or intermediate is basic, the so-called "acid point" can be formed using a specific atom derived from the atomic structure an acidic metal oxide. At this acid point, the acidic metal oxide can be safely bound chemically with the reagent or the intermediate. Further, when the other compound is an amphoteric metal oxide, a specific atom derived from the atomic structure of the amphoteric metal oxide may serve as a base point or an acid point compatible with the properties of the reagent or the intermediate. Therefore, in this case, even when the reagent or the intermediate is any of a basic compound and an acidic compound, the amphoteric metal oxide can be chemically bonded securely with the reagent or the intermediate. In this case, examples of the amphoteric metal oxides include alumina (Al203), zinc oxide (ZnO), and tin oxides (SnO and Sn02). Examples of basic metal oxides include strontium oxide (SrO), barium oxide (BaO), magnesium oxide (MgO), calcium oxide (CaO), rubidium oxide (Rb20), sodium oxide (Na20), and potassium oxide (K20). In addition, examples of acidic metal oxides include phosphorus oxide (P205). In these metal oxides, the formation of the base point or the acid point is attributed to the difference in electronegativity between the metal atom and the oxygen atom that makes up the metal oxide, and the atomic structure of the metal atom and the oxygen atom on the surface of metal oxide. The basic metal oxide, the acidic metal oxide and the amphoteric metal oxide can be suitably selected according to the reagent applied to the catalytic reaction based on the active oxygen species and the intermediate produced from the reactant. It is a matter of course that when zinc oxide is chosen as the photocatalyst, zinc oxide is not chosen as the amphoteric metal oxide, because said zinc oxide is a photocatalyst and at the same time an amphoteric metal oxide. Here, a system in which the photocatalyst is titanium dioxide, the compound is alumina as an amphoteric metal oxide, and the reactant is nitrogen oxide (nitrogen monoxide), will be taken as an example to explain the progress of the reaction catalytic and union using alumina. In this case, nitrogen monoxide is oxidized with a species of active oxygen that is produced by titanium dioxide to give the nitrogen dioxide as an intermediate. As shown schematically in Figure 1, when nitrogen monoxide comes into contact with, or approaches titanium dioxide as the photocatalyst, nitrogen monoxide is oxidized with OH (hydroxyl radical), which is a species of active oxygen that it is produced by titanium dioxide upon exposure to light, to give nitrogen dioxide (gas) (Figure 1 (a)). As is apparent from the molecular structure, nitrogen dioxide is acidic, and alumina is an amphoteric metal oxide with an oxygen atom that serves as the base point for the acidic gas. Therefore, nitrogen dioxide is attracted to and chemically bound to the oxygen atom and held in the alumina (Figure 1 (b)). The force with which nitrogen dioxide is attracted to the oxygen atom is coulombic force and the bond is chemical. Nitrogen dioxide is bound to the oxygen atom of the alumina and remains close to the titanium dioxide as the photocatalyst and is therefore within the system of an oxidation reaction (a catalytic reaction) induced by a hydroxy radical OH (Figure 1 (b)). This ensures the opportunity because the nitrogen dioxide is oxidized with the hydroxy radical 'OH and allows the oxidation of the nitrogen dioxide to proceed efficiently. It is considered that nitrogen dioxide is oxidized to nitrate ions which, together with a hydrogen atom in the hydroxy radical "OH, are bound and maintained in the form of nitric acid (final product) in the oxygen atom, which serves as the base point, of alumina (Figure 1 (c)). When nitrogen dioxide is originally present, that is, when nitrogen dioxide is the reactant, nitrogen dioxide is directly oxidized by a species of active oxygen, which is produced by titanium dioxide and at the same time, nitrogen dioxide chemically bound with alumina as described above, is also oxidized with the active oxygen species.In other words, in this case, the nitrogen dioxide as the reactant is chemically bonded with Next, the bonding using alumina will be explained, in the case when sulfur monoxide (SO) and carbon monoxide (CO) are oxidized with a kind of active oxygen produced by di oxide titanium. Before oxidation, these oxides are converted sulfur dioxide and carbon monoxide, this is again produce acidic gases. For this reason, as schematically illustrated in Figure 2, sulfur dioxide is chemically bonded with oxygen atoms, which are base points that possess alumina as an amphoteric metal oxide and adjacent to it, and which are retained in the alumina. . As illustrated schematically, in Figure 3, in the case of carbon dioxide, the carbon atom and the oxygen atom can be linked in different bonding or bonding orders. Therefore, carbon dioxide is chemically linked to a single oxygen atom as the base point noted above (Figure 3 (a)), or oxygen atoms that serve as the base point and adjacent to it (Figure 3 (b)). )) and that are retained in alumina. In this case, the sulfur dioxide bound and retained in the alumina in this way is further reacted with a species of active oxygen (hydroxy OH radical) which is produced by titanium dioxide to give sulfuric acid or sulfurous acid (final product), while carbon dioxide is converted to carbonic acid (final product). It is considered carbon dioxide that is also converted into methane or methanol by a reaction based on a radical hydrogen atom, generated in the production of the hydroxy (OH) radical as the active oxygen species and the active oxygen species. In this case, methane or methanol can be said to be the final product. According to a fourth preferred embodiment, the other compound is formulated to satisfy a / (a + b) from about 0.0001 to 0.8 where a represents the weight of the other compound and b represents the weight of the photocatalyst. When the value of a / (a + b) is not less than about 0.0001 as specified in the fourth preferred embodiment, the other compound (amphoteric metal oxide, basic metal oxide, or acidic metal oxide) represented by a may advantageously ensure the chemical bonding of the reagent or the intermediate to avoid the reduction of the catalytic reaction efficiency. When the value of a / (a + b) is not greater than about 0.8, the amount of photocatalyst represented by b is advantageously not very small in relation to the other compound, so that reducing the efficiency of the catalytic reaction can be avoided advantageously. In this case, the amount of the photocatalyst can be about 20 to 95% by weight based on the total amount of the photocatalyst, the above compound as a formulation ingredient different from the photocatalyst, and one or other ingredients, if any. According to a fifth preferred embodiment, the photocatalyst and another compound are regulated to and formulated in a range of particle diameter from about 0.005 to 0.5 μm. When the photocatalyst particle diameter and the particle diameter of the other compound (amphoteric metal oxide, basic metal oxide or acidic metal oxide) are in the range of about 0.005 to 0.5 μm as specified in the fifth preferred embodiment, the regulation of the particle diameter can be advantageously carried out by means of an existing milling device, such as a ball mill, or by the sol-gel process. Furthermore, according to the fifth preferred embodiment, there is no significant difference in particle diameter between the photocatalyst and the other compound, the particles of the photocatalyst and the particles of the other compound have a diameter similar to those of the particles of the photocatalyst approach to each other. . Therefore, the other reagent or intermediate chemically linked with the other compound can be approximated to the photocatalyst. This advantageously ensures the opportunity for the catalytic reaction to proceed, achieving improved efficiency. According to a sixth preferred embodiment of the present invention, the photocatalyst formulation further comprises, in addition to the photocatalyst and the other compound, a third component of a compound to which the hydroxyl group is chemically bonded, and chemically adsorbed and retains the hydroxyl group in the surface of the photocatalyst and the compound as the third component, whereby the retained hydroxyl group develops hydrophilicity.

In this sixth preferred embodiment, the hydroxyl group produced through the catalytic reaction, in which the photocatalyst participates, is chemically adsorbed and retained on the surface of the compound as the third component, not to mention in the catalyst. In addition, there is no possibility that the amount of water (water vapor in the air, rainwater or the like) on the surface of the catalyst, becomes zero. Therefore, it can be said that the hydroxyl group always occurs during exposure to light. This allows the hydroxyl group to be maintained at very high density through chemical adsorption bond, such that the hydroxyl group is held firmly. On the other hand, during exposure to light, no hydroxyl groups are produced by the photocatalyst. However hydroxyl groups that have been produced up to this point, are firmly retained on the photocatalyst surface and the compound as the third component, therefore there is no fear that the hydroxyl group is accidentally removed. In this case, when light is again applied, retaining the hydroxyl group at high density is returned even when the hydroxyl density has been decreased to this point. Therefore, according to the sixth embodiment, fixing the photocatalytic formulation on the surface of a certain substrate allows the surface of the substrate to be surely highly hydrophilic, and this high hydrophilicity can be safely maintained for a long period of time. That is, the photocatalyst formulation according to the sixth preferred embodiment can function as a hydrophilicity imparting material, to impart high hydrophilicity to the surface of the substrate. The effects that are achieved by the hydrophilic nature will be described. Hydrophilicity is greatly related to the contact angle between the surface of the material and the water. The greater the hydrophilicity, the smaller the contact angle. When the contact angle is small, water is less likely to remain on the surface of the material. Therefore, in this case, spots deposited on the surface, along with water, run off the surface of the material and are removed from the surface. When the hydrophilicity sufficiently high to exhibit a contact angle below the contact angle of inorganic powder, such as urban powder having a high content of olefinic components and clay mineral, is obtained, the powder can be removed without using the affinity. Furthermore, as the contact angle approaches 0 °, the hydrophilicity is improved and the water diffuses like a film on the surface of the substrate, facilitating the flow of spots. Therefore, not only urban dust but also inorganic powder together with water easily run off onto the surface of the substrate. In this case, the contact angle of preference is not greater than about 20 ° and about 0 ° with a view to improving the anti-fouling effect. Therefore, fixing the photocatalytic formulation according to the sixth preferred embodiment of the invention on the surface of an interior or exterior wall of buildings or the body surface of vehicles, such as automobiles and electric trains, the high hydrophilicity, which It has been taught in this way, it can exhibit a high anti-fouling effect. In this case, when rainwater is sometimes emptied on the surface, due to the high hydrophilicity imparted to its surface, dust and contaminants deposited on the surface, along with rainwater, are washed by surface dragging. each time when the surface is exposed to rainwater, thus allowing the surface to be self-cleaning. That is, the so-called "incrustation by rain blow" can be effectively avoided, where dust or similar streaks are left on streams of water. Furthermore, fixing the photocatalytic formulation according to the sixth preferred embodiment on the surface of glasses, lenses, mirrors or the like can offer a high anti-fogging effect by virtue of the high hydrophilicity. According to a seventh preferred embodiment, the compound as the third component has heat of wetting equal to or greater than that of the photocatalyst. In the case of material with hydroxyl groups present on its surface, the heat of wetting can be considered as an indication of the ability of the surface to retain the hydroxyl groups. The greater the heat of wetting, the higher the surface capacity to retain the hydroxyl groups and the higher the density of the hydroxyl group. Therefore, according to the seventh preferred embodiment, the hydroxyl groups produced by the photocatalyst are chemically adsorbed and retain at higher density in a more effective manner on the compound as the third component. This can impart high hydrophilicity to the substrate surface, with superior reliability for a long period of time. In this case, the wetting heat of titanium oxide, a particularly preferred catalyst is 320 to 512 x 10 ~ 3 Jmf2 for the anatase form and 293 to 645 x 10"3 Jrrf2 for the rutile form. they have a heat of humidification not less than 500 x 10 ~ 3 Jmf2 are more preferred.

According to an eighth preferred embodiment, the compound as the third component is at least one metal oxide selected from Si02, Al203, Zr02, Ge02, Th02 and ZnO. Since these metal oxides have the heat of wetting equal to or greater than titanium oxide, which is particularly preferred as a photocatalyst, the retention density of the hydroxyl group is advantageously improved further. Silica (Si02), alumina (Al203), Ge02 and Th02 are more preferred because the upper limit of the heat of wetting exceeds 1000 x 10"3 Jpf2 In this case, each compound as the third component (Si02, Al203, Zr02 , Ge02, Th02 or ZnO) is determined when taking into consideration the reagent to be reduced by the present invention and a combination with the other compound (A1203, ZnO, SnO, Sn02, SrO, BaO, MgO, CaO, Rb20, K20 or P205 ) formulated together with the photocatalyst, specifically, when Al203 is chosen as the other compound formulated together with the photocatalyst, the compound as the third component is chosen from the group other than A1203, ie it is chosen from Si02, Zr02, Ge02, Th02 and ZnO, in order to avoid the translape of the component.When Al203 as the other compound can not be chemically linked to the reagent or the intermediate, the other compound is chosen from compounds other than ZnO, SnO, Sn02, SrO, BaO, MgO, CaO, Rb20, Na20, K20 and P205 and the third component is chosen from c omitted which include A1203 (this is Si02, Al203, Zr02, Ge02, Th02 and ZnO). This is true for ZnO. According to a ninth preferred embodiment, a fourth component of an antimicrobial metal is added in addition to the photocatalyst, the other compound and the compound as the third component, and the metal, as the fourth component is held in the photocatalyst. In the ninth preferred embodiment, during exposure to light, the antimicrobial activity of the photocatalyst per se is used while during exposure to light, the antimicrobial activity of the metal supported in the photocatalyst is utilized. Therefore, the antimicrobial activity of the photocatalyst can be supplemented, and synergistic antimicrobial activity can be achieved by the antimicrobial metal and photocatalyst. According to a tenth preferred embodiment, the metal as the fourth component has a reduction potential that is no less than the potential of free electrons emitted by the photocatalyst. In this tenth preferred embodiment, the metal can be easily supported in the photocatalyst by taking advantage of the metal reduction potential. In this case, the metal of preference is at least one member selected from silver, copper, palladium, iron, nickel, chromium, cobalt, platinum, gold, lithium, calcium, magnesium, aluminum, zinc, rhodium and ruthenium, because they have the potential of previous reduction. Silver, copper, palladium, platinum and gold are particularly preferred because they have a positive reduction potential and therefore can easily achieve metal containment by reduction. The metal selected as the fourth component of preference is formulated so as to satisfy a c / d value of about 0.00001 to 0.05 where c represents the weight of metal and d represents the weight of the photocatalyst. That is, when the metal as the fourth component has a c / d value not less than 0.00001, there is no possibility that the amount of the metal is too small to exhibit synergistic antimicrobial activity, whereas when the metal as the fourth component has a value c / d not greater than 0.05 (= c / d), there is no possibility that the amount of metal is excessive and adversely affects the catalytic reaction of the photocatalyst. According to a second aspect of the present invention, there is provided a photocatalyst-containing material having a photocatalyst that functions as a catalyst upon exposure to light, the photocatalyst-containing material comprises the photocatalyst formulation according to the first aspect of the invention. present invention, or the photocatalytic formulation according to each embodiment of the first aspect of the present invention, which has been mixed and dispersed in a paint or enamel. As with the photocatalyst formulation according to the first aspect of the present invention, the paint and enamel as the photocatalyst-containing material having the above constitution according to the second aspect of the present invention, can improve the percentage reduction of the reagent or allow the same or the intermediary to be placed safely within the catalytic reaction system. Therefore, the reagent can be efficiently reduced on a surface coated with paint or on a surface with the enamel applied to it. In addition, in these surfaces, the opportunity for the reagent to be applied to the catalytic reaction and the opportunity for the intermediate to be applied further to the catalytic reaction can be ensured, allowing the catalytic reaction to proceed more efficiently. In this case, paints and enamels in which the photocatalyst and the compound are mixed and dispersed, can be conventional paints and enamels. In the case of enamel, the photocatalyst and the compound, together with a starting material of an enamel, for example a frit such as feldspar or potassium carbonate, are dispersed in a solution. By dispersing and mixing the photocatalyst and the compound, the photocatalyst and the compound can be formulated together with the enamel starting material in the course of enamel production. Alternatively, they can be formulated in the complete enamel before it is applied. In the photocatalyst-containing material according to the second aspect of the present invention, when the photocatalyst-containing material according to the second aspect of the present invention is a photocatalyst-containing material (a paint or enamel) such that the Photocatalyst is one that, upon exposure to applied light energy produces excitation electrons and positive orifices that produce one species of active oxygen in the presence of oxygen and water on the surface of the catalyst, and the other compound is at least one metal oxide selected from amphoteric metal oxides, basic metal oxides, and acidic metal oxides which are chemically bound with the reagent or intermediate that is applied to the catalytic reaction, based on the active oxygen species, the following advantage can be offered.

According to this photocatalyst-containing material, as with the above embodiments of the photocatalyst formulation according to the first aspect of the present invention, the reagent or the intermediate can be safely bound and retained at the base point or the acid point, and the Reagent or the intermediate can be placed within the catalytic reaction system based on the active oxygen species. This allows the catalytic reaction to proceed more efficiently on a surface coated with the paint as the material containing photocatalyst or a surface with the applied enamel, which in turn can improve the percentage reduction of the reagent. In addition, in the photocatalyst-containing material, when using the photocatalyst formulations containing the compound as the third component specified in the sixth to eighth preferred embodiments of the photocatalyst formulation according to the first aspect of the present invention, it can be achieved in these surfaces advantageously a high anti-fouling effect based on high hydrophilicity. In addition, in the photocatalyst-containing material, when using the photocatalyst formulations containing the metal as the fourth component specified in the ninth to tenth preferred embodiments, of the photocatalyst formulation according to the first aspect of the present invention, it can advantageously be achieved synergistic antimicrobial activity on these surfaces by the antimicrobial metal and the photocatalyst. In the photocatalyst-containing material according to the present invention, particularly the paint, a coating of the photocatalyst-containing material can be formed by painting on interior or exterior walls of building structures, such as existing buildings, houses and existing fountains and structures. such as rail protectors and protective barriers and barriers against road noise. Therefore, these structures can be easily modified to have a high percentage of reagent reduction and high anti-fouling effect. According to a third aspect of the present invention, there is provided a photocatalytically activatable material comprising a substrate layer and a surface layer that is provided on the surface of the substrate layer, the photocatalytically activatable material becomes photocatalytically active upon exposure to the light, the surface layer comprising the photocatalyst formulation according to the first aspect of the present invention, the photocatalyst formulation according to each embodiment of the first aspect of the present invention, or the photocatalyst-containing material according to the second aspect of the present invention. In the photocatalytically activatable material according to the third aspect of the present invention, when the surface layer comprising a photocatalytic formulation or a photocatalyst-containing material comprising the compound as the third component or a combination of the compound as the third component with the metal as the fourth component, the surface layer can have a geometry that satisfies any of the following requirements (1) and (2): (1) surface layer thickness: approximately 0.01 to 3.0 μ; and (2) the difference in color of the surface layer between before ultraviolet irradiation and after ultraviolet irradiation of the surface layer with a deposited 1% silver nitrate solution, for 5 minutes at an ultraviolet intensity in the surface layer of 1.2 mW / cm2,? E: 1 to 50. In the photocatalytically activatable material according to this embodiment, the surface layer contains the compound as the third component. As with the sixth to eighth preferred embodiments of the photocatalytic formulation according to the first aspect of the present invention, by virtue of the compound as the third component, the surface layer has a reduced contact angle and improved hydrophilicity which can achieve a high anti-fouling effect. When the thickness of the surface layer is not less than about 0.01 μm, the layer (surface layer) is not too thin and is advantageous since the contact angle of the surface layer per can surely be used as the contact angle of the material . Specifically, even when the substrate has a high contact angle, the surface layer that is provided in the substrate can reduce the contact angle as the material. Therefore, the material can exhibit a high anti-fouling effect. On the other hand, when the thickness of the surface layer is not greater than about 3.0 μm, adhesion of the surface layer to the substrate can be maintained. This can advantageously prevent the separation of the surface layer (layer separation). This is true with respect to the use of the compound as the third component in combination with the metal as the fourth component. Silver ions, in the silver nitrate solution deposited in the surface layer, are reduced and precipitated to develop a color, as a result of reception of excitation electrons from the photocatalyst in the excited state upon exposure to ultraviolet light. Therefore, a difference in color? E is observed between before ultraviolet irradiation and after ultraviolet irradiation of the surface layer. The greater the amount of excited electrons produced, the greater the difference in color? E. The amount of excited electrons produced is a factor that regulates the photoactivity of the photocatalyst. This allows the photocatalytic activity to be evaluated when using the color difference? E. Exciting electrons from the photocatalyst produce active oxygen species such as hydroxy OH radical in the air. Therefore, the greater the photocatalytic activity, that is, the greater the color difference? E, the greater the number of active oxygen species, such as hydroxy OH radical. The compound as the third component contained in the surface layer functions to retain the hydroxyl radical OH produced by the electrons of excitation of the photocatalyst. The greater the amount of hydroxyl radical OH produced, the higher the hydroxyl group density on the surface of the compound will be as the third component. This provides a lower contact angle with water and therefore can improve hydrophilicity. In addition, the greater the amount of OH hydroxy radical produced, the greater the amount of organic compounds that are decomposed or decomposed. This is advantageous for hydrophilicity. Therefore, when the surface layer has a color difference? E not less than 1, it has a sufficiently high photocatalytic activity to form a high density of hydroxyl groups. Advantageously, this can surely reduce the contact angle of the surface layer to a sufficiently low level to provide anti-fouling effect. On the other hand, when the quantity of photocatalyst is increased based on the binder per unit surface area, the color difference increases? E. In this case, it is considered that the adhesion to the substrate is reduced causing the separation of the surface layer. For this reason, a surface layer having a color difference ΔE not greater than 50 is preferred to avoid separation of the surface layer. According to a fourth aspect of the present invention, there is provided a photocatalytically activatable material comprising a substrate layer and a surface layer which is provided on the surface of the substrate layer, the photocatalytically activatable material becomes photocatalytically active upon exposure to the light, the surface layer has been formed using the photocatalytic formulation according to the first aspect of the present invention or the photocatalytic formulation according to each embodiment of the first aspect of the present invention on the surface of the substrate layer, through a binder. In the photocatalytically activatable material according to the fourth aspect of the present invention, the binder is preferably one that is polymerized or fused below a temperature, in which the material quality of the substrate layer is changed, to bind the Photocatalytic formulation on the surface of the substrate layer or alternatively an enamel or a paint is preferable. According to a fifth aspect of the present invention, there is provided a photocatalytically activatable material, comprising a substrate layer and a surface layer that is provided on the surface of the substrate layer, the photocatalytically activatable material becomes photocatalytically active upon exposure to the light, the surface layer comprising Ti02 as a photocatalyst and in addition Al203, Si02 and an antimicrobial metal. As with the photocatalytic formulation according to the first aspect of the present invention, in photocatalytically activatable materials having the above constitution according to the third to fifth aspects of the present invention, in the surface layer that is provided in the substrate layer , the percentage reduction of the reagent can be improved and the reagent or intermediate can surely be placed within the catalytic reaction system. Therefore, in the surface layer of the photocatalytically activatable material, the reagent can be efficiently reduced, at the same time it is the opportunity for the reagent to be applied to the catalytic reaction and the opportunity for the intermediate to be applied further to the catalytic reaction, You can make sure, allowing it to proceed more efficiently. In addition, since the surface layer contains an antimicrobial metal, in the surface layer, antimicrobial synergistic activity can be advantageously achieved by the antimicrobial metal and photocatalyst. When the photocatalytically activatable materials according to the third and fourth aspects of the present invention are photocatalytically activatable materials such that, the photocatalyst is one which, upon exposure to applied light energy, produces excitation electrons and positive orifices which produce a kind of active oxygen in the presence of oxygen and water on the surface of the catalyst, and the other compound is at least one metal oxide selected from amphoteric metal oxides, basic metal oxides and acidic metal oxides which are chemically bound with the reactant or the intermediary that is applied to the catalytic reaction based on the active oxygen species, the following advantages can be offered. According to these photocatalytically active materials, as with the above embodiments of the photocatalyst formulation according to the first aspect of the present invention, the reagent or intermediate can surely be ligated and maintained at the base point or the acid point and the reagent or the intermediary it can be placed within the catalytic reaction system based on the active oxygen species. This allows the catalytic reaction to proceed more efficiently in the surface layer in the photocatalytically addressable material, which in turn can improve the percentage reduction of the reagent. In addition, in the photocatalytically activatable materials, when the photocatalyst formulations or photocatalyst-containing materials containing the compound are employed as the third component specified in the sixth to eighth preferred embodiments of the photocatalyst formulation according to the first aspect of the present invention, A high anti-fouling effect based on high hydrophilicity on these surfaces can advantageously be achieved. Furthermore, in photocatalytically activatable materials, when photocatalytic formulations or photocatalyst-containing materials are used and which have the metal as the fourth component specified in the preferred embodiments ninth to tenth of the photocatalytic formulation according to the first aspect of the present invention invention, the synergistic antimicrobial activity can advantageously be achieved on these surfaces by the antimicrobial metal and photocatalyst. In the photocatalytically activatable materials according to the third to fifth aspects of the present invention, the following preferred embodiments can be adopted. According to a first preferred embodiment, the substrate layer comprising a substrate selected from ceramics, resins, metals, glasses, pottery or earthenware, woods, calcium silicate boards, concrete boards, cement boards, cement boards extruded, gypsum boards and lightweight concrete boards in auto-clave. According to this preferred embodiment, the photocatalytically activatable material can act photocatalytically at sites where these substrates are used, for example interior and exterior walls of building structures, such as building structures, such as buildings, houses and bridges and roads, and decompose environmental pollutants, such as nitrogen oxides, sulfur oxides and carbon dioxide to purify the air. In addition, when the photocatalytic formulation containing the compound is used as the third component, the photocatalytically activatable material can exhibit a high anti-fouling effect based on the high hydrophilicity in the interior and exterior walls of the construction, roads and the like. According to a second preferred embodiment, the surface layer has been formed by thermal treatment, for example, by burning. According to this embodiment, a surface layer that has adhered to the substrate layer can be strongly formed. According to a third preferred embodiment, an antimicrobial metal or metal compound is anchored to the surface of the surface layer. According to this embodiment, during exposure to light, the antimicrobial activity of the photocatalyst per se in the surface layer is used, while during non-exposure to light, the antimicrobial activity of the metal anchored to the surface layer is used and by therefore, the antimicrobial activity of the photocatalyst can be supplemented. Furthermore, since the surface layer contains the other compound described above apart from the photocatalyst, the surface layer, in addition to the antimicrobial action, can decompose the environmental contaminants and purify the air through an improvement in the efficiency of the catalytic reaction, in where the photocatalyst participates. In addition, in the photocatalytically activatable material, when photocatalyst formulations or photocatalyst containing materials are used which contain the compound as the third component specified in the sixth to eighth preferred embodiments of the photocatalyst formulation according to the first aspect of the present invention, A high anti-fouling effect based on high hydrophilicity is advantageously achieved in these surface layers. In addition, in the photocatalytically activatable materials, when the photocatalyst formulations or materials containing the photocatalyst are used with the metal with the fourth sustained component specified in the preferred embodiments ninth to tenth of the photocatalytic formulation according to the first aspect of the present invention invention, synergistic antimicrobial activity may advantageously be achieved by the metal as the fourth component. Therefore, the amount of metal or metal compound anchored in the surface layer can be minimized. In addition, when the synergistic antimicrobial activity achieved by the metal as the fourth component is high, the anchoring of metal or metal compound on the surface layer can be omitted. According to a sixth aspect of the present invention, there is provided a process for producing a photocatalytically activatable material comprising a substrate layer and a surface layer that is provided on the surface of the substrate layer, the photocatalytically activatable material becomes photocatalytically active upon exposure to light, the process comprises the steps of: providing the photocatalytic formulation according to the first aspect of the present invention or the photocatalytic formulation according to each embodiment of the first aspect of the invention. present invention or a photocatalytic formulation dispersed in sol with the dispersed catalyst formulation therein; layering the photocatalytic formulation or the photocatalytic formulation dispersed in sol on the surface of the substrate layer (layer forming step); and form the surface layer.

In this case, the photocatalytic formulation dispersed in sol can be obtained by dispersing the photocatalytic formulation in a liquid such as water or an alcohol. The process according to the sixth aspect of the present invention does not require any special stage.

Therefore, a novel photocatalytically activatable material can be easily produced, which as described above in connection with the photocatalyst formulation according to the first aspect of the present invention, allows the reagent or intermediate to be safely placed within the reaction system catalytic, which is carried out a catalytic reaction with high efficiency in the surface layer. In this case, by forming the surface layer, suitable methods may be adopted, for example heat treatment or drying treatment according to the layered catalytic formulation or the photocatalytic formulation dispersed in sol. In the process according to the sixth aspect of the present invention, when the step of layering involves the step of placing, coating, or printing the photocatalytic formulation or the photocatalytic formulation dispersed in sol on the surface of the substrate layer to form a layer of the photocatalytic formulation or the photocatalytic formulation dispersed in sol, the following advantages are offered. Specifically, according to the process according to the sixth aspect of the present invention, a novel photocatalytically activatable material comprising a photocatalytic formulation can be easily produced and can create a catalytic reaction with high efficiency in a surface layer having a substantially uniform thickness. When the formation of a coating in layers is contemplated, the formation of layers of the photocatalytic formulation on the surface of the substrate layer can be carried out by a convenient coating method, such as spray coating, whereas when the formation is contemplated of a layered print, the layering of the photocatalytic formulation on the surface of the substrate layer can be carried out by a convenient printing method such as roll printing. According to a seventh aspect of the present invention, there is provided a process for producing a photocatalytically activatable material, comprising a substrate layer and a surface layer that is provided on the surface of the substrate layer, the photocatalytically activatable material is activated upon exposure in light, the process comprises the steps of: providing the photocatalytic formulation according to the first aspect of the present invention, the photocatalytic formulation according to each embodiment of the first aspect of the present invention or a photocatalytic formulation dispersed in sol with the photocatalytic formulation there dispersed; layering a binder on the surface of the substrate layer to form a binder layer; layering the photocatalytic formulation or the photocatalytic formulation dispersed in sol on the surface of the binder layer; and thermo-treating the structure according to the properties of the binder, to form the surface layer. In the process according to the seventh aspect of the present invention, the surface layer can be formed on the surface of the binder layer, such that, at the interface of the binder layer and the surface layer, the photocatalytic formulation in the layer Surface is embedded and retained in the binder layer.

This allows the surface layer to be firmly anchored on the binder layer and at the same time, the photocatalyst formulation is effectively contacted with the external air. In addition, a novel photocatalytically activatable material can be provided, which as described above in connection with the photocatalyst formulation according to the first aspect of the present invention, the reagent or the intermediate that is safely placed within the catalytic reaction system, allowing the catalytic reaction to be carried out with high efficiency in the surface layer. In this case, when the surface layer is formed using an enamel as the binder, the heat treatment can be carried out at a temperature of 30 to 300 ° C above the enamel softening temperature and below the temperature at which the enamel softens. The quality of the substrate that constitutes the substrate layer is changed. The heating temperature of at least 30 ° C over the softening temperature of the binder (enamel) is advantageous since an unnecessarily long period of time is not required to soften the enamel by heating. Furthermore, since the heating temperature is not a temperature higher than 300 ° C above the enamel softening temperature, quick melting of the enamel can be avoided, avoiding unfavorable phenomena, such as excessive incrustation of the photocatalytic formulation, the creation of uneven surface or creation of sting holes. Furthermore, in forming the surface layer, the heat treatment is preferably carried out at a temperature of about 150 to about 1300 ° C. This allows an existing heating device to be used in the production of a novel photocatalytically activatable material that creates the catalytic reaction with high efficiency. The heat treatment temperature of about 150 ° C or higher complies with the thermal treatment temperature of conventional glazes, eliminating the need for using heat treatment conditions that are different from those in the prior art. Furthermore, when the heat treatment temperature is about 1300 ° C or lower, the temperature is adapted to that of heat treatment used in substrates that require heat treatment, for example in the production of mosaics or ceramic materials, eliminating the need to change the thermal treatment conditions. When the surface layer is formed using a paint as the binder, the heat treatment can be carried out below a temperature at which the quality thereof constituting the substrate layer is changed. This advantageously allows the formation of the substrate layer without changing the quality of the substrate. In the processes according to the sixth and seventh aspects of the present invention, the step of forming the surface layer can be followed by the step of coating a solution containing a metal or antimicrobial metal compound dispersed in the surface layer and the step of Anchor the metal or a metal oxide in the surface layer. In the process for producing a photocatalytically activatable material according to this embodiment, this novel photocatalytically activatable material can be easily produced, wherein the surface layer can exhibit antimicrobial activity regardless of whether the material is placed under light conditions or under dark conditions, and in addition, a highly efficient catalytic reaction is carried out in the surface layer. In addition, regardless of whether the material is placed under light conditions or under dark conditions, this property of exhibiting antimicrobial activity can be imparted after the surface layer is formed in the photocatalytically activatable material. In the processes according to the sixth and seventh aspects of the present invention, the step of forming layers can comprise forming layers of the photocatalytic formulation or the photocatalytic formulation dispersed in sol and then coating a solution containing a metal or antimicrobial metal compound. therein dispersed, and the step of forming the surface layer comprises, simultaneously with the formation of the surface layer, anchoring the metal or metal oxide in the surface layer. In the process to produce a photocatalytically activatable material according to this modality, a novel photocatalytically activatable material can be easily produced, having from the first, both the property of exhibiting the antimicrobial activity regardless of whether the material is placed under light conditions or under dark conditions, and the property of creating the catalytic reaction with high efficiency. In the processes according to the sixth and seventh aspects of the present invention, the step of forming the surface layer can be followed by the step of coating an aqueous metal salt solution containing antimicrobial metal ions in the surface layer and the stage of irradiating the surface layer with ultraviolet light to photoreduce the metal ions in the photocatalyst, thereby supporting and fixing the metal in the photocatalyst in the surface layer. In the process for producing a photocatalytically activatable material according to this embodiment, a novel photocatalytically activatable material can be easily produced, which in the surface layer, can exhibit the antimicrobial activity, regardless of whether the material is placed under light conditions or under of darkness, and at the same time can develop a catalytic reaction in the surface layer with high efficiency. In addition, a metal, which contributes to supplement the antimicrobial activity, is held and fixed in the photocatalyst in the surface layer through photoreduction and is therefore less likely to separate from the photocatalyst. Therefore, the property of supplementing the antimicrobial activity can be maintained for a long period of time. In addition, regardless of whether the material is placed under light conditions or under dark conditions, this property of exhibiting antimicrobial activity can be imparted after the surface layer is formed in the photocatalytically activatable material. When the photocatalytic formulation with the metal as the fourth metal supported there according to the ninth and tenth embodiments in the photocatalytic formulation according to the first aspect of the present invention is used, the metal as the fourth component can also develop synergistic antimicrobial activity. . Therefore, the amount of metal supported in the surface layer through coating of the aqueous metal salt solution and subsequent ultraviolet irradiation can be minimized. In addition, when the antimicrobial synergistic activity of the metal as the fourth component is high, the step of supporting the metal in the surface layer can be omitted. According to an eighth aspect of the present invention, there is provided a process for producing a photocatalyst formulation comprising photocatalyst which functions as a catalyst upon exposure to light, the other compound, the compound as the third component and metal as the catalyst. fourth component, the process is characterized in that it comprises the steps of: providing a photocatalyst dispersed in sol containing there dispersed, at least the photocatalyst between the photocatalyst, the other compound and the compounds as the third component; and a process for producing a photocatalyst formulation comprising a photocatalyst which, upon exposure to light, functions as a catalyst, comprising the steps of: providing a photocatalytic formulation dispersed in sol, with the photocatalyst formulation according to any of the embodiments preferred sixth to eighth in the first aspect of the present invention, there dispersed; and mixing the photocatalyst formulation dispersed in sol with an aqueous metal salt solution containing antimicrobial metal ions and supporting the metal as the fourth component in the photocatalyst. According to a ninth aspect of the present invention, there is provided a process for producing the photocatalyst formulation, comprising the photocatalyst which functions as a catalyst upon exposure to light, the other compound, the compound as the third component and the metal as the fourth component, the process is characterized in that it comprises the steps of: providing a photocatalyst dispersed in sol containing at least the photocatalyst dispersed between the photocatalyst as the other compound and the compound as the third component; and mixing the photocatalyst dispersed in sol with an aqueous metal salt solution containing antimicrobial metal ions, co-precipitating the metal salt and the photocatalyst formulation and holding the metal as the fourth component in the photocatalyst. According to a tenth aspect of the present invention, there is provided a process for producing the photocatalyst formulation comprising the photocatalyst which functions as a catalyst upon exposure to light, the other compound, the compound as the third component and the metal as the fourth component, the process is characterized in that it comprises the steps of: providing a photocatalyst dispersed in sol containing there dispersed, at least the photocatalyst between the photocatalyst, the other compound and the compound as the third component; and mixing the photocatalyst dispersed in sol with an aqueous metal salt solution containing antimicrobial metal ions and then irradiating the mixture with ultraviolet light to photoreduce the metal ions, thereby supporting the metal as the fourth component in the photocatalyst. In the processes for producing a photocatalytic formulation according to the eighth to tenth aspects of the present invention, a novel photocatalytic formulation can easily be produced which, in the surface layer formed using the photocatalytic formulation, can exhibit antimicrobial activity, regardless of whether the Material is placed under light conditions or under dark conditions, and at the same time can develop a catalytic reaction in the surface layer with high efficiency. Furthermore, in the process according to the eighth aspect of the present invention, what is required to previously hold and fix the metal that contributes to supplement the antimicrobial activity on the photocatalyst, is simply to mix the photocatalyst dispersed in sol with the solution of aqueous metal salt. This can simplify the process. In addition, in the process according to the ninth and tenth aspects of the present invention, co-precipitation or photoreduction is used to previously support and fix a metal that can supplement the antimicrobial activity on the photocatalyst. By virtue of this constitution, the metal is less likely to separate from the photocatalyst, allowing the ability to supplement the antimicrobial activity that is maintained for a long period of time. Furthermore, in the process according to the tenth aspect of the present invention, what is required to support and fix the metal, is simply to apply ultraviolet light and the use of chemical products and the like is not required in fact. This can simplify the process. In the processes for producing a photocatalytic formulation according to the eighth to tenth aspects of the present invention, the sun with dispersed photocatalyst can be a sun containing there dispersed, all the photocatalyst, the other compound, and the compound as the third component, that is, a sun containing there disperses the photocatalytic formulation according to the sixth modes preferred octave in the first aspect of the present invention. In addition, the other compound and the compound as the third component can be dispersed in the dispersed sol in photocatalyst after supporting the metal. Further, when the photocatalyst formulation should be powdery from the storage convenience or the like point of view, a sol can be dried containing, dispersed as the photocatalyst, with the metal as the fourth component there supported, the other compound and the compound as the third component. The present invention can take the following other modalities. Specifically, according to a first other embodiment of the present invention, there is provided a process for producing a formulation containing a photocatalyst that can function as a catalyst upon exposure to light, the process is characterized in that it comprises the steps of: ) provide a first sun containing scattered photocatalyst particles there; (B) providing a second sol containing dispersed there, particles of the other compound that are chemically bound to the reagent or an intermediate that is produced before the reagent becomes the final product before the catalytic reaction; and (C) mixes the first sun with the second sun.

In the process according to this first other embodiment, mixing the first sol with the second sol allows the photocatalyst and the other compound to be easily dispersed in a solvent. In the mixed sun, which has been subjected to step (C), not only the photocatalyst agglomerates nor only the other compound agglomerates and the resulting sol is such that the photocatalyst and the other compound constituting the photocatalyst formulation are mixed and they disperse in a substantially intimate way. Therefore, this mixed sun is suitable for use as a photocatalytic formulation dispersed in sol. This facilitates the formulation of, for example, a material that is used in a liquid state, for example the formulation of the photocatalyst and the other compound in paints or enamels. In addition, by virtue of the sun shape, the first and second soles can be easily weighed. The mixing ratio of photocatalyst with the other compound can be easily regulated by weighing the first and second soles. In addition, removal of the solvent in the mixed sol by drying or other means may provide a solid particulate formulation, comprising a substantially intimate mixture of the photocatalyst with the other compound.

In this case, an identical solvent is preferably used for the first sol and the second sol, or solvents having the so-called "good affinity". In the process according to the first other embodiment of the present invention, step (A) may involve the step of preparing photocatalyst particles which, upon exposure to applied light energy, produce excitation electrons and positive orifices that produce a species of active oxygen in the presence of oxygen and water on the surface of the catalyst, and step (B) may involve the step of providing as the other compound, at least one metal oxide selected from amphoteric metal oxides, basic metal oxides and acidic metal oxides which are chemically bound with the reagent or the intermediate to be applied to the catalytic reaction based on the active oxygen species and to prepare metal oxide particles. According to this second other embodiment, a photocatalytic formulation comprising a substantially intimate mixture of a photocatalyst, capable of causing a catalytic reaction based on active oxygen species, can be easily produced with the other compound capable of safely binding and retaining the reagent. or the intermediary at the base point or the acid point.

In the process according to the other first embodiment, step (C) may involve the step of formulating the first sol with the second sol, such that a / (a + b) is approximately 0.0001 to 0.8, where a represents the weight of the metal oxide and b represents the weight of the photocatalyst. According to this third other embodiment, a photocatalytic formulation can easily be produced wherein the amount of the metal oxide (amphoteric metal oxide, basic metal oxide or acidic metal oxide) is not too small and the amount of photocatalyst is not too much. small in relation to the metal oxide, in such a way that reducing the efficiency of the catalytic reaction can be avoided. In addition, in the process according to the first other embodiment, step (A) may involve the step of regulating particles of the photocatalyst to a diameter in the range of about 0.005 to 0.5 μm, and step (B) may involve the step of regulating metal oxide particles to a diameter in the range of about 0.005 to 0.5 μm. According to this fourth other embodiment, the particle diameter can be easily regulated by subjecting the photocatalyst and the metal oxide (amphoteric metal oxide, basic metal oxide or acidic metal oxide) to treatment by an existing milling device such as ball mill, or by the sol-gel process. A photocatalytic formulation that does not cause a reduction in the efficiency of the catalytic reaction, it can be easily produced without separating the reagent or the intermediate from the photocatalyst. In addition, according to this embodiment, photocatalyst particles and particles of the metal compound having diameters similar to those of the photocatalyst particles can be approximated with each other and the reagent or intermediate can approach the photocatalyst. This allows a photocatalyst formulation that can provide high catalytic reaction efficiency to be easily produced. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram illustrating, in oxidation of nitrogen oxides with titanium dioxide as a photocatalyst, the progressing state of a catalytic reaction and the binding state of an intermediate, produced by the reaction catalytic in alumina in the case where it is formulated together with titanium dioxide; Figure 2 is a schematic diagram illustrating, in the oxidation of sulfur oxides with titanium dioxide as a photocatalyst, the binding state of an intermediate, produced by the catalytic reaction, in alumina in the case where the alumina together with Titanium dioxide are formulated; Figure 3 is a schematic diagram illustrating, in oxidation of carbon monoxide with titanium dioxide as a photocatalyst, the progressing state of a catalytic reaction and the binding state of an intermediate, which is produced by the catalytic reaction, in alumina, in the case where it is formulated together with titanium dioxide; Figure 4 is a schematic block diagram of a test apparatus used in the measurement of the effect of reducing nitrogen oxides by exemplary mosaics according to the first example of the present invention; Figure 5 is a graph showing the results of a test on the effect of reducing nitrogen oxides by example mosaics according to the first example of the present invention; Figure 6 is a graph showing the results of a test on the ammonia reducing effect by the example tiles according to the first example of the present invention; Figure 7 is a graph showing the results of a test on the effect for reducing sulfur dioxides by exemplary mosaics according to the first example of the present invention; Figure 8 is a graph showing the results of a test on the effect of reducing nitrogen oxides by exemplary mosaics according to the first example of the present invention; Figure 9 is a graph showing the results of a test on the effect of reducing nitrogen oxide by exemplary mosaics, according to the first example of the present invention; Figure 10 is a graph showing the results of a test on the antimicrobial effect by the exemplary mosaics, according to the third example of the present invention; Figure 11 is a graph showing the relationship between c / d (proportion of metal formulation), where the weight of a supported metal is shown in the exemplary tiles (baked type) of a four-component system according to the sixth example and d represents the weight of Ti02 supported and the antimicrobial activity; Figure 12 is a graph showing the relationship between c / d (proportion of metal formulation), where c represents the weight of a metal supported in the exemplary mosaics (paint type) of a four component system according to the sixth example and d represents the weight of the Ti02 supported in the mosaics and the antimicrobial activity; Figure 13 is a graph showing the relationship between the thickness of the surface layer and the contact angle under light conditions in the exemplary mosaics of a four-component system (baked type) according to the sixth example; Figure 14 is a graph showing the relationship between the thickness of the surface layer and the antimicrobial activity in the exemplary mosaics of a four-component system (baked type) according to the sixth example of the present invention; Figure 15 is a graph showing the relationship between the thickness of the surface layer and the oil degradation activity in the exemplary mosaics of a four-component system (baked type) according to the sixth example; Figure 16 is a graph showing the relationship between the thickness of the surface layer and the oxidation activity of NO in the exemplary mosaics of a four-component system (baked type) according to the sixth example; Figure 17 is a graph showing the relationship between the thickness of the surface layer and the contact angle under light conditions in the exemplary mosaics of a three-component system (baked type) according to the seventh example; Figure 18 is a graph showing the relationship between the color difference ΔE and the contact angle under light conditions in the exemplary mosaics of a four component system (paint type) according to the sixth example; Figure 19 is a graph showing the relationship between the color difference ΔE and the antimicrobial activity in the exemplary mosaics of a four component system (paint type) according to the sixth example; Figure 20 is a graph showing the relationship between the color difference ΔE and the oil degradation activity in the exemplary mosaics of a four component system (paint type) according to the sixth example; Figure 21 is a graph showing the relationship between the color difference ΔE and the oxidation activity of NO in exemplary mosaics of a four component system (paint type) according to the sixth example; and Figure 22 is a graph showing the relationship between the color difference ΔE and the contact angle under light conditions in the exemplary mosaics of a three-component system (paint type) according to the seventh example. BEST MODE FOR CARRYING OUT THE INVENTION Next, modalities will be described with reference to the following examples. Preparation of photocatalyst formulations used in the following examples will be described. Titanium dioxide (anatase form) is used as a photocatalyst that is formulated together with the photocatalyst. Alumina as an amphoteric metal oxide and strontium oxide and barium oxide as base metal oxides were used as metal oxides. Photocatalyst formulations were prepared through the following steps. (i) Supply of photocatalyst and metal oxide particles Starting materials were provided for titanium dioxide, alumina, strontium oxide and barium oxide. All were pulverized by means of a grinding device such as a ball mill, or subjected to a sol-gel process. In this way, fine particles of titanium dioxide, alumina, strontium oxide and barium oxide were obtained. In this case, the size regulation was carried out in such a way that for the particles of the compounds the diameter is in the range of approximately 0.005 to 0.5 μm. (ii) Preparation of sol Next, the prepared formulation materials thus prepared were dispersed in a solvent, such as water or an alcohol, to prepare one sol for each material for formulation. In this case, for each sol, the amount of material to be dispersed (for example, the weight of the material for formulation / volume of the solvent) is specified. (iii) Preparation of photocatalyst formulations Subsequently, the titanium dioxide sol (photocatalyst sol) prepared in this way was mixed with a sol dioxide metal, that is, an alumina sol, a strontium oxide sol or a sol of barium oxide. In this way, a mixed sun of titanium dioxide / alumina (sun Ti / Al), a mixed sun of titanium dioxide / strontium oxide (sun Ti / Sr), a mixed sun of titanium dioxide / barium oxide ( sun Ti / Ba) were obtained. In the preparation of mixed sols, the photocatalyst sol and the metal dioxide sol were weighed, and the mixed sols with varying formulation ratios of the photocatalyst and the metal oxide were prepared by varying the amount by weight of the photocatalyst sol to be mixed and the amount heavy sun metal oxide to mix. Specifically, mixed soles were prepared with the formulation ratio defined as a / (a + b) (the "a / (a-b)" below will be referred to as the "formulation ratio"), where a represents the weight of the metal oxide in each mixed sun and b represents the weight of the photocatalyst in each mixed sun. In addition to the above steps (i) to (iii), alumina particles or the like, which have been regulated to a desired particle size, can be added to and dispersed in the photocatalyst sol to prepare a Ti / Al sol or similar. In addition, photocatalyst particles that have been regulated to a desired particle size and alumina particles or the like can be dispersed alternately or simultaneously in the solvent to prepare a Ti / Al sol or similar with the photocatalyst and alumina particles or the like scattered originally there. Then, photocatalytically activatable materials having photocatalytic activity using the photocatalytic formulations (mixed Ti / Al sol, Ti / Sr mixed sol and Ti / Ba mixed sol) thus prepared, will be described. In the present example (first example), mosaics were used as the photocatalytically activatable material and produce as follows. An unglazed mosaic was provided as a substrate. Each of the mixed soles having a specified concentration was spray coated on the surface of the mosaic. In the spray coating, the coverage, ie the dew time, was regulated in such a way that the thickness of the photocatalyst formulation layer on the surfaces of the mosaic after baking was approximately 0.85 μm. The mosaics that have been spray-coated with the mixed soles were then baked at a certain temperature by taking into consideration the melting temperature of the silica or the like formulated to fix the photocatalyst and the melting temperature of the titanium dioxide and each oxide. metal (approximately 800 ° C in this example) for approximately 60 minutes. In this manner, photocatalytically activatable end materials comprising a surface layer containing the neutral sol materials (photocatalyst and alumina or the like) provided on the surface of a substrate (mosaic) were obtained. These photocatalytically activatable materials were evaluated as follows. The evaluation was carried out in terms of the effect of reducing nitrogen oxides, ammonia and sulfur dioxide that are desired to be reduced as harmful materials in the air or in the environment. The evaluation test will be briefly described. At the beginning, an evaluation test will be described to reduce nitrogen oxides. It should be noted that, for the mixed sun spray coating, spin coating, dip coating and the like, of course can be adopted instead of spray coating. (1-1) Evaluation test 1: Effect of alumina and the like to reduce nitrogen oxides For comparison with products according to the examples of the present invention, a photocatalytically activatable mosaic using a photocatalytic formulation that does not contain alumina, strontium oxide and barium oxide with only formulated titanium dioxide (a comparative mosaic) and photocatalytically activatable mosaics according to the examples of the present invention (exemplary mosaics) were prepared as follows. The comparative mosaic is prepared by spray coating a photocatalyst sol having a titanium dioxide content of 7.5% by weight on the surface of the mosaic and baking the coated mosaic under the above conditions (approximately 800 ° C x 60 minutes). The spray coating time, and the like, were determined such that the weight of titanium dioxide on the surface of the mosaic after baking was approximately 3.3 x 10 ~ 4 g / cm2 (thickness of titanium dioxide layer: approximately 0.85). μm). The exemplary mosaics were the following Ti / Al mosaic, Ti / Sr mosaic and Ti / Ba mosaic. The Ti / Al mosaic is prepared by spraying a Ti / Al sol with a titanium dioxide content of 7.5% by weight and a proportion of alumina formulation regulated to 1/11 in terms of the proportion of formulation to / (a + b) (a Ti / Al sol with the proportion by weight of titanium dioxide to alumina is 0.1) in the same manner as described above in connection with the comparative mosaic and baking the coated mosaic therein as described earlier in connection with the comparative mosaic. The Ti / Sr mosaic is prepared by spray coating a Ti / Sr sol comprising titanium dioxide and strontium oxide in the same formulation ratio as described above in connection with the Ti / Al mosaic and baking the coated mosaic in the same way as described above in connection with the comparative mosaic. The Ti / Ba mosaic is also prepared in the same way as described above. The comparative mosaic only has titanium dioxide on the surface of the mosaic and exhibits catalytic activity as a standard for comparison. Thus, the comparison with each one of the exemplary mosaics of the comparative mosaic, shows whether or not an improvement in the catalytic activity has been achieved when formulating the metal oxide and the degree of improvement. The comparative mosaic comprises a mosaic having a surface layer consisting of titanium dioxide alone. On the other hand, each of the exemplary mosaics comprises a mosaic having a surface layer formed of a formulation of titanium dioxide and alumina, strontium oxide or barium oxide. The comparative mosaic and exemplary mosaics were tested as follows. In the test, a piece of sample that has a size of 10 square cm was used for each of the comparative mosaics and the exemplary mosaics. For each of the sample pieces, the effect of reducing nitrogen oxide is measured in a test apparatus shown in Figure 4. In this test apparatus, a cylinder 12 filled with nitrogen monoxide gas having a constant concentration, it is provided upstream of a hermetically sealed glass cell 10 where the sample piece is placed. Gas NO of the cylinder 12 is mixed with air, which has been sucked through an air pump 14 and adjusted to the desired unit by means of a humidity controller 15, through a valve for flow rate control 16. The gas NO (test gas) having a predetermined concentration (approximately 0.95 ppm) is circulated at a constant speed (1 liter / minute) through the flow control valve 16 inside the glass cell 10. A meter Concentration (NOx detector) 18 for measuring the concentration of nitrogen oxides in the gas, which has been passed through the cell, is provided downstream of the glass cell 10. The NOx detector 18 is constructed in such a manner that the concentration of NO and the concentration of nitrogen dioxide (concentration N02) in the gas are measured at any time. The measured value of the NO concentration is added to the measured value of the N02 concentration, and the sum of both concentrations is sent out as the nitrogen oxide concentration (NOx concentration). The test apparatus is provided with a lamp 20 for applying ultraviolet light (wavelength 300 to 400 nm) in the glass cell 10. The lamp 20 is illuminated with control such that the intensity of the ultraviolet light in the stub sample is 1.2 mW / cm2. The piece of sample is placed in the glass cell 10 of the test apparatus, that is, placed under an environment that is subjected to ultraviolet irradiation. For each of the comparative mosaic and the exemplary mosaics, the N02 concentration and the NOx concentration were plotted against the time elapsed since the start of the test gas circulation. The results are illustrated in Figure 5. The lamp 20 was not turned on until the NOx concentration (NO concentration) on the outlet side was stable after the start of the test gas flow. In the evaluation test 1, if a reaction is not carried out to oxidize nitrogen monoxide for example, if the glass cell 10 is placed in a dark room so as not to produce active oxygen species by titanium dioxide in the surface layer and causing a catalytic reaction, the test gas is circulated in the NOx detector 18 without causing any reaction. Therefore, in this case, the output of the NOx detector 18 is identical to the test gas concentration (CNO / input) for NO concentration (CNO / output), the concentration of N02 (CN02 / output) is zero with NOx concentration (CNOx / output) which is CNO / output, this is identical to CNO / entry. However, when NO is oxidized by a catalytic reaction based on active oxygen species produced by titanium dioxide in the surface layer, the concentration of NO is reduced by CNO / input by an amount of NO that has been oxidized. In addition, when N02 produced by the oxidation of NO is released from the surface of the mosaic, the concentration of N02 is increased by an amount of N02 that is released. The degree of reduction in NOx is determined from the relationship between the reduction in NO concentration by oxidation of NO and the increase in concentration of N02 by releasing the N02 formed on the surface of the mosaic. As illustrated in Figure 5, for the comparative mosaic, the NOx concentration is reduced rapidly at the start of the test. After approximately 5 minutes elapsed since the start of the test, the NOx concentration increases and approaches the test gas concentration. In addition, for the comparative mosaic, the concentration of N02 increases after the start of the test and 30 minutes after the start of the test reaches approximately 0.18 ppm. The concentration of NOx and the concentration of N02 increased substantially in the same way. These indicate that, for the comparative mosaic, the photocatalyst reaction by titanium dioxide in the surface layer proceeds to oxidize NO, resulting in reduced NO concentration. In this case, an increase in N02 concentration inhibits the reduction of all NOx. Therefore, for the comparative mosaic, since N02 is detached from the mosaic surface, greater oxidation of N02 on the mosaic surface is not significant. The concentration of NOx 30 minutes after the start of the test was approximately 0.66 ppm and therefore the NOx reduction of the comparative mosaic was approximately 30.5% ((0.95 - 0.66) / 0.95). On the other hand, for all the exemplary mosaics of the Ti / Al mosaic, Ti / Sr mosaic and Ti / Ba mosaic, as with the comparative mosaic, the NOx concentration quickly decreases when the test is started. Subsequently, the NOx concentration is maintained at a value slightly higher than the minimum concentration. In addition, for the exemplary mosaics, the concentration of N02 was not significantly increased after the start of the test and even 30 minutes after the start of the test, it was as low as approximately .05 ppm. From these facts, it can first be said that for the exemplary mosaics, the photocatalytic reaction by titanium dioxide in the surface layer proceeds to oxidize NO, resulting in reduced concentration of NO. In addition, N02 is bound with alumina, strontium oxide and barium oxide and therefore does not release relatively from the mosaic surface, and further oxidation of N02 with titanium dioxide proceeds actively, such that the concentration is not increased of N02. For this reason, for exemplary mosaics, NOx can be reduced with very high efficiency. The concentration of NOx 30 minutes after the start of the test was approximately 0.45 ppm, and therefore the reduction of NOx in the exemplary mosaics was approximately 52.6% ((0.95-0.45) / 0.95), that is, it was substantially the double of the comparative mosaic. For exemplary mosaics, the previous test was continued. As a result, it was found that the high reduction in NOx was maintained. The test was finished 12 hours after the start of the test. The surface of the exemplary mosaics was washed with water and the washing liquid was analyzed for the materials contained therein. As a result, the presence of nitric acid was confirmed. In addition, all the exemplary mosaics had an excellent surface without unacceptable irregularities. A slip abrasion test was carried out using a plastic eraser in accordance with JIS A 6808. As a result, for all exemplary mosaics, after reciprocating slip approximately 40 times, the surface layer did not cause deterioration or separation, indicating that the abrasion resistance was excellent. This means that the photocatalyst formulation produced by the mixing of the sols as described above can also be applied not only to paints and glazes or baked glazes but also to baking, printing, binders and the like. In addition, the photocatalyst formulation and the photocatalytically activatable material which can highly reduce nitrogen oxides by virtue of the photocatalytic activity, can easily be produced by mixing sols as described above. (1-2) Evaluation test 1: Effect of alumina and similar in reduction in ammonia Also, for ammonia, the reduction by the comparative mosaic, the Ti / Al mosaic and the Ti / Sr mosaic, was investigated using the same apparatus and method described above in connection with nitrogen oxides. In this case, the test gas that circulated in the glass cell 10 was approximately 4 ppm of ammonia gas. The concentration of ammonia in the gas, which has been passed through the cell, was determined with a concentration meter (a gas detector tube) that is provided downstream of the cell. For the comparative mosaic and the exemplary mosaics (Ti / Al mosaic and Ti / Sr mosaic), the concentration of ammonia was plotted against the time elapsed from the start of the circulation of the test gas. The results are illustrated in Figure 6. As shown in Figure 6, for all of both the comparative mosaic and the exemplary mosaics, the concentration of ammonia was reduced before the start of the test. Over time, the exemplary mosaics provided a lower concentration of ammonia than the comparative mosaic. Approximately 10 minutes after the start of the test, the mosaics provided substantially constant respective ammonia concentrations. Specifically, the ammonia concentration was approximately 3.5 ppm for the comparative mosaic, approximately 2.5 ppm for the Ti / Al mosaic and approximately 2.6 ppm for the Ti / Sr mosaic. The reduction in ammonia was approximately 12.5% ((4-3.5) / 4) for the comparative mosaic, approximately 37.5% ((4-2.5) / 4 for the Ti / Al mosaic and approximately 35% ((4 - 2.6) / 4) for the Ti / Sr mosaic From these facts, it was apparent that for the comparative mosaic, the photocatalytic reaction by titanium dioxide in the surface layer proceeds to develop chemical conversion of ammonia to NO, N02 and the like, reducing ammonia in certain proportion, while for both the mosaic specimens, Ti / Al mosaic and Ti / Sr mosaic, the reduction in ammonia was higher than for the comparative mosaic.The reason for this is considered to be as follows: If the reaction for ammonia conversion In these materials (chemical conversion) is not carried out, the test gas circulates in the gas detector tube without causing any reaction.In this case, the measured value of the ammonia concentration is identical to that of the test gas. However, when catalytic action ammonia based on the active oxygen species produced by titanium dioxide in the surface layer and converted into other materials, the concentration of ammonia is reduced from the concentration of ammonia in the test gas by an amount of ammonia that It has become. For this reason, both for the comparative mosaic and the example mosaics, the concentration of ammonia is reduced immediately after the start of the test. In this case, since ammonia is catalytically reacted based on the active oxygen species, nitrogen that constitutes ammonia is oxidized to give NO and N02 as intermediates. It is considered that, as previously described, NO is oxidized with N02 by the active oxygen species and N02 is further oxidized by the active oxygen species and consequently chemically converted to nitric acid., resulting in improved chemical conversion of ammonia to NO and N02 through the catalytic reaction of ammonia based on the active oxygen species that can improve the reduction in ammonia. The exemplary mosaics are different from the comparative mosaic since as previously described alumina or strontium oxide which bind to N02 to prevent N02 from detaching from the surface of the mosaic / have been formulated. For the comparative mosaic, N02 produced from ammonia is released from the surface of the mosaic and for this reason greater oxidation of N02 by the active oxygen species to chemically convert N02 into nitric acid does not proceed significantly. In contrast, for example mosaics, N02 produced from ammonia is not left on the surface of the mosaics and this promotes greater oxidation of N02 in nitric acid by the active oxygen species. For this reason, for the mosaics, as described above, the reduction in ammonia was improved. It is considered that this has created superiority of the reduction in ammonia by the exemplary mosaics with respect to the comparative mosaic. (1-3) Evaluation Test 1: Effect of alumina and similar in reduction in sulfur dioxide Also for sulfur dioxide, the reduction by the comparative mosaic and the Ti / Al mosaic is investigated using the same apparatus and method as described above in connection with nitrogen oxides. In this case, the test gas that circulated inside the glass cell 10 was about 10 ppm of the sulfur dioxide gas. The concentration of sulfur dioxide in the gas, which has passed through the cell, is determined with a concentration meter (a gas detector tube) that is provided downstream of the cell. For the comparative mosaic and the exemplary mosaic (Ti / Al mosaic) the concentration of sulfur dioxide is plotted against the time elapsed from the beginning of the flow of the test gas. The results are shown in Figure 7. As illustrated in Figure 7, both for the comparative mosaic and the exemplary mosaic, the concentration of sulfur dioxide was reduced before the start of the test. Over time, the exemplary mosaic provides a lower concentration of sulfur dioxide than the comparative mosaic. Approximately 30 minutes after the start of the test, the concentration of sulfur dioxide was approximately 7.7 ppm for the comparative mosaic and approximately 2.7 ppm for the Ti / Al mosaic. In this way, the reduction between sulfur oxide was about 23% ((10 - 7.7) / 10) for the comparative example and about 73% ((110 - 2.7) / 10) for the Ti / Al mosaic. From these facts, it was apparent that for the comparative mosaic, the photocatalytic reaction by titanium dioxide in the surface layer proceeds to develop chemical conversion of sulfur dioxide, sulfuric acid, sulfurous acid or the like, reducing the sulfur dioxide in certain proportion, while for the Ti / Al mosaic (exemplary mosaic) the reduction of sulfur dioxide was higher than for the comparative mosaic. The reason for this is considered as follows.

The reason why both the comparative mosaic and the exemplary mosaic reduces the concentration of sulfur dioxide is that, as in the case of nitrogen monoxide and ammonia, azure dioxide is catalytically reacted based on active oxygen species produced by titanium dioxide in the surface layer and converted to sulfuric acid or sulfurous acid. In this case, the concentration of sulfur dioxide is reduced from the concentration of sulfur dioxide in the test gas by an amount of sulfur dioxide that has been converted. Sulfur dioxide as the reactant is an acid gas. Therefore, as explained with reference to Figure 2, sulfur dioxide which is the reagent in this evaluation test, is chemically bonded and adsorbed on alumina as a basic metal oxide. For this reason, for the alumina-free comparative mosaic, sulfur dioxide is oxidized by the active oxygen species and chemically converted to sulfuric acid or sulphurous acid in such a state that it is not adsorbed on the surface of the mosaic. Therefore, this reaction proceeds relatively lightly. In contrast, for the exemplary mosaic, sulfur dioxide is oxidized by the active oxygen species and converted to sulfuric acid or sulphurous acid in a state which is such that it is adsorbed on the surface of the mosaic. This promotes the reaction. For this reason, for the exemplary mosaic as described above, the reduction in sulfur dioxide is improved. It is considered that this has created superiority of the reduction in sulfur dioxide by the exemplary mosaic with respect to the comparative mosaic. Next, the ratio between the proportion of alumina or the like that has been formulated together with the photocatalyst, and the effect of reducing nitrogen oxides, is evaluated by the following two methods. This evaluation is carried out by taking alumina as an example. (2) Evaluation Test 2: Ratio effect of alumina formulated to reduce nitrogen oxides - part 1 Initially, for comparison with products according to the examples of the present invention, a comparative mosaic and photocatalytically activatable mosaics of the example (mosaics) copies) that were similar to those used in the evaluation test, are provided as follows. The comparative mosaic is prepared by spray coating a photocatalyst sol having a titanium dioxide content of 7.5% by weight on the surface of the mosaic and baking the coated mosaic under the above conditions (approximately 800 ° C x 60 minutes). In the spray coating, the coating time and the like were determined, such that the weight of titanium dioxide on the surface of the mosaic after baking was approximately 3.3 x 10 ~ 4 g / cm2 (thickness of the dioxide layer). titanium: approximately 0.85 μm). The exemplary mosaic was the following Ti / Al mosaic. The Ti / Al mosaic is prepared by spray coating a photocatalyst sol having a titanium dioxide content of 7.5% by weight, which was the same as that of the comparative mosaic, and a proportion of alumina formulation regulated to 0.0001 a 0.8 in terms of the formulation ratio a / (a + b) and baking the coated mosaic in the same manner as described above in connection with the comparative mosaic. Specifically, various Ti / Al mosaics were baked where the weight of titanium dioxide on the surface of the mosaic after baking was identical to that of the comparative mosaic and approximately 3.3 x 10 ~ 4 g / cm2 while the weight of alumina on the surface of the mosaic after baking was varied. These Ti / Al mosaics were used as exemplary mosaics in the evaluation test 2. When the formulation ratio a / (a + b) is 0.01, a = b / 99. Therefore, in this case, the weight of alumina on the surface of the mosaic after baking is approximately 3.3 x 10 ~ 6 g / cm2. On the other hand, when the formulation ratio is a / (a + b) is 0.5, a = b. Therefore, in this case the weight of alumina on the surface of the mosaic after baking is approximately 3.3 x 10"4 g / cm 2. Also, in this evaluation test 2, since the comparative mosaic exhibits standard catalytic activity, the comparison of the comparative mosaic with the Ti / Al mosaics, with the amount of formulated alumina varied reveals the effect of the amount of alumina formulated on an improvement in catalytic activity where the amount of the photocatalyst is identical. using the same test apparatus used in the evaluation test 1, and 30 minutes after the start of the test, that is, the start time of the flow of a test gas having a predetermined concentration (approximately 0.95 ppm) at a constant speed and the start of the ignition of lamp 20, the concentration of N02 and the concentration of NOx were measured for the comparative mosaic and the exemplary mosaics. or of the tiles, the amount of NOx removed, which is determined by subtracting the average value of the NOx concentration from the NO concentration of the test gas, and the measuring value of the N02 concentration were plotted. The results are illustrated in Figure 8. For the comparative mosaic, since the alumina was not actually formulated, the formulation ratio a / (a + b) was zero. In Figure 8, the results in the comparative mosaic (a / (a + b) = 0) are plotted on the Y axis, in the graph. As is notable from Figure 8, for the comparative mosaic, the concentration of N02 was approximately 0.17 ppm, while the amount of NOx removed was approximately 0.3 ppm. The reason why, although the NOx concentration was reduced to a value lower than the Nox concentration in the test gas, the presence of N02 not contained in the test gas is detected is that, as described above, the photocatalytic reaction by titanium dioxide in the surface layer proceeds and N02 detaches from the surface of the mosaic. By contrast, for the Ti / Al mosaic of which the formulation ratio a / (a + b) is represented on the X coordinate axis, when the amount of alumina formulated was small, that is, the formulation ratio a / ( a + b) was 0.01, the concentration of N02 was approximately 0.15 ppm, while the amount of NOx removed was approximately 0.4 ppm. For the Ti / Al mosaic, where the amount of alumina formulated was identical to that of titanium dioxide, that is, the formulation ratio a / (a + b) was 0.5, the concentration of N02 was approximately 0.14 ppm, while that the amount of NOx removed was approximately 0.43 ppm. For the Ti / Al mosaic where the formulation ratio a / (a + b) was 0.05 to 0.2, the concentration of N02 was approximately 0.06 to 0.13 ppm, while the amount of NOx removed was approximately 0.44 to 0.46 ppm. In this way, compared to the comparative mosaic, these Ti / Al mosaics provide much lower concentration of N02 and much greater amount of NOx removed. Also, for the Ti / Al mosaic where the formulation ratio a / (a + b) was 0.0001, the results (concentration N02 = approximately 0.155 ppm; amount of NOx removed = approximately 0.36 ppm) were similar to the Ti / Al mosaic where the formulation ratio a / (a + b) was 0.01. The results in this Ti / Al mosaic are not indicated in this drawing because the trace on the axis of the X coordinate for the Ti / Al mosaic was close to zero. As it is apparent from these facts, when the formulation ratio A / (a + b) is in the range of 0.0001 to 0.5, the alumina formulation can prevent N02 from detaching from the surface of the mosaic, achieving superior reduction of N02 and its superior reduction of NOx than the comparative mosaic. A formulation ratio a / (a + b) in the range of 0.05 to 0.2 is particularly preferred because a much greater reduction in NOx than the comparative mosaic can be achieved. Furthermore, even when the amount of alumina formulated is very small, that is, even when the formulation ratio a / (a + b) is 0.0001, high NOx reduction can be provided. In addition, the Ti / Al mosaics with the varied formulation ratio a / (a + b), also had a good surface and possesses excellent abrasion resistance. (3) Evaluation Test 3: Ratio effect of alumina formulated by reducing nitrogen oxides - part 2 In this evaluation test 3, the total amount of titanium dioxide as the photocatalyst and alumina (the sum of the amounts of both materials formulated) was constant, with the proportion of titanium dioxide to alumina being varied to examine the effect of reducing nitrogen oxides. Initially, for comparison with product according to the examples of the present invention, a comparative mosaic and photocatalytically activatable mosaics of examples (exemplary mosaics) that were similar to those used in the evaluation test 1, were provided as follows. The comparative mosaic was identical to the comparative mosaic used in evaluation test 2, and the weight of titanium dioxide on the mosaic surface after baking was approximately 3.3 x 10"" 4 g / cm2. A simple mosaic (mosaic having no photocatalytic activity) using a formulation containing only alumina without any photocatalyst is also provided where the weight of alumina on the mosaic surface was approximately 3.3 x 10 ~ 4 g / cm2. The following Ti / Al tiles were provided as the exemplary mosaics. The Ti / Al mosaics were prepared by coating with a Ti / Al sol spray with the total amount of titanium dioxide and alumina which is the same as in the comparative mosaic. That is, 7.5% by weight and having a proportion in alumina formulation regulated to 0.05 to 0.95 in terms of the formulation ratio a / (a + b) in the same way as described above in connection with the comparative mosaic and baking the coated mosaics in the same manner as described above in connection with the comparative mosaic. Specifically, various Ti / Al tiles were baked where the weight of titanium dioxide on the surface of the mosaic after baking is reduced by about 3.3 x 10 ~ 4 g / cm2 with increase in the weight of alumina. These Ti / Al mosaics were used as the exemplary mosaics in the evaluation test 3. When the formulation ratio a / (a + b) is 0.05, a + b corresponds to 3.3 x 10"4 g / cm2 above. Thus, the weight a of alumina on the surface of the mosaic after baking is approximately 1.65 x 10"5 g / cm2, while the weight b of titanium dioxide is approximately 3.135 x 10 ~ 4 g / cm2. On the other hand, when the formulation ratio a / (a + b) is 0.95, the weight a of alumina is approximately 3.135 x 10 ~ 4 g / cm2, while the weight b of titanium dioxide is approximately 1.65 x 10" 5 g / cm2 Also, in this evaluation test 3, since the comparative mosaic exhibits standard catalytic activity, the comparison of the comparative mosaic with the Ti / Al mosaics with the formulated amounts of titanium dioxide and alumina varied, reveals the effect of the amounts of titanium dioxide and alumina formulated in an improvement in catalytic activity. In this evaluation test 3, the same test apparatus used in the evaluation test 1 was used, and the concentration of N02 and the amount of NOx removed were plotted or plotted in the same way as the evaluation test. The results are illustrated in Figure 9. For the comparative mosaic, since the alumina has not been formulated in fact, the formulation ratio a / (a + b) was zero. For the mosaic that does not exhibit any photocatalytic activity, since titanium dioxide has not been formulated in fact, the formulation ratio a / (a + b) was 1.

In Figure 9, the results in the comparative mosaic (a / (a + b) = 0) were plotted on the Y axis in the graph. As it is apparent in Figure 9, for the comparative mosaic, the concentration of N02 was approximately 0.17 ppm, while the amount of NOx removed was approximately 0.3 ppm. The reason why the presence of N02 not contained in the test gas is detected despite reducing the concentration of NOx to a value lower than the concentration of NOx in the test gas, is as described above in connection with the evaluation test 2. For the simple mosaic that does not exhibit any photocatalytic activity, the results were plotted on the axis of the X coordinates of the graph. As it is apparent from the graph, both the concentration of N02 and the amount of NOx removed were of course zero. By contrast, for the Ti / Al mosaic of which the formulation ratio a / (a + b) is indicated on the X coordinate axis in the graph, when the amount of alumina formulated was small, that is, the proportion of formulation a / (a + b) was 0.05, the concentration of N02 was approximately 0.07 ppm, while the amount of NOx removed was approximately 0.46 ppm. For the Ti / Al mosaic, where the amount of alumina formulated was greater than that of the formulated titanium dioxide and the formulation ratio a / (a + b) was 0.8, the concentration of N02 was approximately 0.13 ppm, while the The amount of NOx removed was approximately 0.32 ppm. For Ti / Al mosaic where the formulation ratio a / (a + b) was 0.05 to 0.65, the concentration of N02 was approximately 0.07 to 0.09 ppm, while the amount of NOx removed was approximately 0.43 to 0.52 ppm. In this way, in comparison with the comparative mosaic, these Ti / Al mosaics provide much lower N02 concentration and much greater amount of NOx removed. For Ti / Al mosaics, where the amount of formulated alumina is male greater than that of formulated titanium dioxide and the formulation ratio a / (a + b) is 0.9, or more, the concentration of N02 and the amount of NOx removed were no more than those for the comparative mosaic. As is apparent from the above facts, when the formulation ratio a / (a + b) is in the range of 0.0001 to 0.8, with the total amount of titanium dioxide and constant alumina, the alumina formulation can prevent N02 from leaving the surface of the mosaic, achieving higher reduction of N02 and in turn higher NOx reduction, than the comparative mosaic. A formulation ratio a / (a + b) in the range of 0.05 to 0.6 is particularly preferred because a much higher NOx reduction than the comparative mosaic can be achieved. When the formulation ratio a / (a + b) is less than 0.0001 or exceeds 0.8, the NOx reduction similar to that of the comparative mosaic can be provided. However, in particular, when the formulation ratio a / (a + b) is not less than 0.9, the amount of titanium dioxide as the photocatalyst is so small that the particles of titanium dioxide are surrounded by alumina particles without leave space This is expected to prevent light from reaching titanium dioxide resulting in reduced photocatalytic activity. In addition the Ti / Al mosaics with the varied formulation ratio a / (a + b) also had a good surface and possess excellent abrasion resistance. In the first example, the anatase form of titanium dioxide is employed as the photocatalyst and alumina as amphoteric metal oxide and strontium oxide and barium oxide as basic metal oxides, were employed as the metal oxide to be formulated together with the photocatalyst. The NOx reduction however can of course be provided by other photocatalysts in combination with other metal oxides. For example regarding titanium dioxide as the photocatalyst, the crystal form can be rutile or brookite. further, the use of photocatalysts such as ZnO, V205, 03, Sn02, SrTi03, Bi203 and Fe203 can also provide the effect of reducing NOx. In addition, the effect of reducing NOx can be provided by using zinc oxide and tin oxide (such as amphoteric metal oxides) and magnesium oxide, calcium oxide, rubidium oxide, sodium oxide and potassium oxide (as metal oxides) basic) instead of alumina, strontium oxide and barium oxide as metal oxide. When the gas to be reduced is a basic gas, phosphorus oxide (acidic metal oxide) can be used in addition to the amphoteric metal oxides. Next, the second example will be described. In this second example, the process for forming the surface layer of a photocatalyst formulation, comprising a photocatalyst, such as titanium dioxide, and a specific metal oxide such as alumina that is provided on the surface of the mosaic, is different from that one. in the first example. In the second example, a substrate in which a surface layer is to be formed first is provided. Substrates usable here include ceramics, resins, metals, glass, earthenware, woods, calcium silicate boards, concrete boards, cement boards, extruded cement boards, gypsum boards and autoclave lightweight concrete boards. As far as the substrate is concerned those used in construction structures such as buildings, houses and bridges, and barriers for road sound, environmental pollutants such as nitrogen oxides can be advantageously reduced in the system of these building structures to purify the air. A layer of binder is then formed on the surface of the substrate. For the formation of the binder layer, a binder material having a softening temperature lower than a temperature at which the quality of the substrate is changed is chosen. The binder layer is formed using the selected binder material by a convenient method, compatible with the properties of the binder. For example, when the substrate is a mosaic, an enamel or ceramic, an enamel or glaze layer or a printing layer for conducting dye or the like on the surface, it can be as such employed as the binder layer. After the formation of the binder, a photocatalyst formulation layer, which subsequently serves as the surface layer, is formed by coating or printing a sol, such as a Ti / Al sol in the first example, on the surface of the layer binder or when applying a mixture of particles, particles of titanium dioxide with alumina particles, which is obtained by removing the solvent from the sol. Alternatively, a photocatalytic formulation layer may be formed in a formed binder layer followed by mounting the binder layer on the surface of the substrate. What is required here is that the photocatalyst formation layer is formed in the binder layer such that these two layers do not separate from each other before subsequent burning. Subsequently, when the binder layer is formed of a glaze layer, the heat treatment is carried out under an environment having a temperature of 30 to 300 ° C above the softening temperature of the binder material (glaze) and below the temperature of the binder material. temperature at which the quality of the substrate changes. The heat treatment allows the binder material (glaze) is founded and solidifies. Consequently, the binder layer is firmly fixed on the surface of the mosaic and at the same time, a surface layer constituted by the photocatalytic formulation layer is formed. In this case, at the boundary between the surface layer and the binder layer, photocatalyst formulation particles (titanium dioxide particles and alumina particles) in the surface layer settle in the binder layer during the melting of the binder material. The particles are embedded and retained in the binder layer and this allows the surface layer to be tightly fixed on the binder layer. Furthermore, in the photocatalytic formulation layer, adjacent particles are linked together by intermolecular force between particles and by sintering before baking to form the surface layer. In this surface layer, particles of titanium dioxide and alumina particles are exposed on their surface. This allows the surface layer to be firmly fixed on the binder layer and at the same time allows particles of titanium dioxide and alumina particles to effectively come into contact with the external air. Therefore, in the process according to the second example, materials of construction structure and the like, can easily be produced having a surface layer capable of inducing a photocatalytic reaction with high efficiency. In this case, the heating temperature of at least 30 ° C over the softening temperature of the binder material is advantageous since not much unnecessary time is required to soften the binder material and there is no adverse effect on sedimentation and retention of the particles of titanium dioxide and alumina. Furthermore, since the heating temperature is not higher than 300 ° C above the temperature at which the binder is subjected to a change in quality, a rapid melting of the binder material can advantageously be avoided, avoiding problems such as excessive sedimentation of particles of alumina and titanium dioxide, creating irregularities in the surface and the creation of pitting. The heating temperature is preferably 50 to 150 ° C above the softening temperature of the binder material. Also, in the second example, with respect to titanium dioxide as the photocatalyst, the crystalline form can also be rutile or brookite. Also, ZnO, V205? 03; Sn02r SrTi03; Bi203 and Fe203 can also be used as the photocatalyst. When the gas to be reduced is an acid gas such as NOx, it is possible to use zinc oxide and tin oxide (such as amphoteric metal oxide), magnesium oxide, calcium oxide, rubidium oxide, sodium oxide and potassium oxide. (as basic metal oxide) instead of alumina as metal oxide. When the gas to be reduced is a basic gas, phosphorus oxide (acidic metal oxide) can be used in addition to the amphoteric metal oxides. Next, other examples will be described. In the first and second examples, the photocatalyst and the specific compound described above retain a reagent (for example NO) or an intermediate (for example N02) within the catalytic reaction system to ensure the opportunity for the reagent to be applied to the reaction catalytic or the opportunity for the intermediate to be applied additionally to the catalytic reaction, whereby the effect of reducing harmful materials such as NOx is achieved. In the following examples, in addition to the specific compounds described above, other compounds are added to further improve the effect of reducing NOx or achieving effects that have not been described above. The third example will be described. The third example demonstrates a photocatalytically active material that can provide a catalytically efficient reaction and at the same time has antimicrobial activity created upon production of active oxygen species by the photocatalyst. By producing photocatalytically activatable material, two soles are provided. One of the sols is a Ti / Al sol with alumina, together with titanium dioxide formulated at the formulation rate described above, which can provide a catalytically efficient reaction. The other sun, is a third sun with particles of copper (Cu), copper oxide, silver (Ag) or silver oxide dispersed there. Next, the Ti / Al sol is coated on the surface of a mosaic and the lining is baked to form a Ti / Al layer. Subsequently, the third sol is coated on the surface of the Ti / Al layer that is provided on the surface of the mosaic and the third sun component is fixed on the surface of the Ti / Al layer by photoreduction or the like. This mosaic is a mosaic of the third example. The mosaic of the third example has a surface layer with titanium dioxide as the photocatalyst, together with alumina which is fixed on top, and copper or other particles are fixed on the surface layer. In the preparation of the third sun, the coverage is regulated in such a way that the photocatalyst is satisfactorily exposed to light. For example, a copper weight of about 0.8 to 2.0 μg / cm2 after baking is sufficient for satisfactory results. The mosaic of the third example and the comparative mosaic used in the previous evaluation tests were evaluated for the following antimicrobial activity. The antimicrobial activity is evaluated based on whether the mosaic or does not have the effect of killing Escherichia coli (strain Escherichia coli w3110). At the beginning, the mosaic surface of the third example and the surface of the comparative mosaic are sterilized with 70% ethanol. Subsequently, 0.15 ml (1 to 5 x 104 CFU) of a suspension of Escherichia coli are dropped on the surface of the mosaics. A glass plate is placed on the surface of the mosaics in such a way that Escherichia coli comes into intimate contact with the surface of the mosaics. In this way, samples were prepared. In this case, a couple of samples were prepared for each of the mosaics. A sample for each of the exemplary mosaics of the third example and the comparative mosaic is irradiated with light from a fluorescent lamp through the glass plate. The other sample for each of the exemplary mosaics of the third example and the comparative mosaic is placed under an environment protected from light. The survival rate of Escherichia coli in the samples under fluorescent light irradiation conditions (under light conditions) and the samples under conditions protected from light (under dark conditions) is measured over time. The antimicrobial activity (proportion of Escherichia coli that have been exterminated or subjected to growth braking) determined from the survival rate is plotted against the elapsed time. The results are shown in Figure 10. In the measurement of the survival rate, the Escherichia coli suspension in each of the samples was cleaned with a sterile gauze and collected in 10 ml of physiological saline, and the survival rate of Escherichia coli in the physiological saline is measured and considered as the survival rate in the sample. As apparent from Figure 10, under conditions of fluorescent light irradiation, both the exemplary mosaic of the third example and the comparative mosaic had high antimicrobial activity. This is probably because under conditions of fluorescent light irradiation, the active oxygen species have been actively produced by titanium dioxide in the surface layer and have decomposed the organic components of Escherichia coli to kill or stop the growth of Escherichia coli. Under conditions protected from light, the comparative mosaic does not produce the active oxygen species and therefore had no substantial antimicrobial activity, while the exemplary mosaic of the third example had relatively high antimicrobial activity even under light-protected conditions., because Cu or other fixed particles on the surface exhibit antimicrobial action even under protected conditions against light. Thus, in the exemplary mosaic of the third example, under conditions protected from light, the antimicrobial action, which can not be achieved by titanium dioxide as the photocatalyst due to the state protected from light, can be achieved by Cu or other particles and therefore, it can supplement the antimicrobial action of the photocatalyst. Also, in the third example, with respect to titanium dioxide as the photocatalyst, the crystalline form can be rutile or brookite. In addition, ZnO, V205 (03 / Sn02; SrTi03 / Bi203"and Fe203 can also be used as the photocatalyst Zinc oxide and tin oxide (such as amphoteric metal oxides), magnesium oxide, calcium oxide, rubidium oxide, sodium oxide and potassium oxide (as oxides) of basic metal) and phosphorus oxide (such as acidic metal oxide) can be used instead of alumina such as metal oxide, copper oxide, silver, (Ag), silver oxide, and metals which have antimicrobial activity as such ( even low antimicrobial activity) such as palladium, nickel, cobalt, platinum, gold, aluminum, iron, zinc, chromium, rhodium and ruthenium can preferably be used instead of copper, and then the fourth and fifth examples will be described. formulation of the fourth example is of a four component system comprising the photocatalyst and alumina or other metal oxide (amphoteric metal oxide, basic metal oxide, or acidic metal oxide) as with the first and second examples and in addition, a compound different from that described above and metal such as copper or silver, as used in the third example. The formulation of the fifth example is of a three component system comprising the photocatalyst, alumina or other metal oxide (amphoteric metal oxide, basic metal oxide or acidic metal oxide), and in addition, a compound different from that described above. In the fourth example, the metal used in combination with the other ingredients is preferably a metal that has a potential for reduction over the potential (-3.2 V) of free electrons released from titanium dioxide as the photocatalyst, because the metal can be supported in titanium dioxide by the reduction potential (support by reduction). Specific examples of these metals usable herein include transition metals such as silver, copper, palladium, iron, nickel, chromium, cobalt, platinum, gold, lithium, calcium, magnesium, aluminum, zinc, rhodium and ruthenium. Among them, silver, copper, palladium, platinum and gold are particularly preferred because they have a positive reduction potential and therefore are likely to create support by reduction. In use of these metals in combination with the other ingredients, methods for supporting the metal on the catalyst will be described. Usable methods for supporting the metal on the photocatalyst are as follows. (i) Simple mixing: An aqueous metal salt solution containing a contemplated metal species is added to and mixed by a photocatalyst sol to adsorb metal ions onto the surface of the photocatalyst particles, thereby supporting the metal on the photocatalyst. (ii) Coprecipitation: An aqueous metal salt solution containing a contemplated metal species is added to a photocatalyst sol, followed by addition of a precipitant or heating to simultaneously precipitate the metal salt and the photocatalyst, this is to cause coprecipitation. In this way, metal ions are supported on the particle surface of the photocatalyst. (iii) Support before photoreduction: An aqueous metal salt solution containing a contemplated metal species is added to a photocatalyst sol, and the mixture is irradiated with ultraviolet energy. In this way, the metal is supported on the particle surface of the photocatalyst by using photoreduction of the metal ions. (iv) Support after photoreduction: An aqueous metal salt solution containing a contemplated metal species is coated on a photocatalyst film, followed by irradiation with ultraviolet energy. In this way, the metal is supported on the surface of the photocatalyst film by using photoreduction of the metal ions. (v) Vapor Deposition: A metal contemplated in a particulate or composite form is held by physical or chemical vapor deposition. (vi) Other: Ions of a contemplated metal species are added before the photocatalyst is granulated by the sol-gel process, followed by coprecipitation or the like to form the metal / photocatalyst ions. Silicon dioxide (silica: SiO2) is used as the compound used in combination with the photocatalyst and the metal oxide, such as alumina. Zr02, Ge02; Th02, ZnO and other oxides can be used instead of silica. In the fourth example, simple mixing, support prior to photoreduction, or coprecipitation is adopted, and photocatalysts were used with metals supported by this method. In the photocatalyst activatable mosaic (exemplary mosaic) according to the fourth example, photocatalyst sols containing a photocatalyst (titanium dioxide), with silver or copper supported there, dispersed there by simple mixing, with support before photoreduction or coprecipitation they provided. In the same way as described above in connection with the evaluation test 1 in the first example, soles of two other ingredients (alumina and silica) were mixed with photocatalyst soles with a metal supported on the photocatalyst (metal / photocatalyst) and the mixture is stirred. The mixed suns were coated by dew on the mosaic, followed by baking. In this way, exemplary mosaics of the fourth example were prepared that were of a four component photocatalyst / metal (silver or copper) / alumina / silica system. In this case, in order to investigate the influence of additionally formulated metal and silica, a mosaic of a two-component system of photocatalyst / metal (silver or copper) (reference mosaic) was also prepared. Exemplary mosaics of the fifth example were prepared as follows. A photocatalyst sol containing a photocatalyst (titanium dioxide) was provided only as described in the first example. In the same manner as described above in connection with the evaluation test 1 in the first example, soles of two other ingredients (alumina and silica) were mixed with the photocatalyst sol, and the mixture was stirred. The mixed sun was coated by dew on the mosaic, followed by baking. In this way, exemplary mosaics of the fifth example were prepared, which were from a three component photocatalyst / alumina / silica system. The exemplary mosaics and the reference mosaic of the fourth and fifth examples, the exemplary mosaic of the first example and the comparative mosaic were evaluated for NOx reduction. The exemplary mosaic of the first example and the comparative mosaic were those as described above in connection with the evaluation test 1 in the first example. For the exemplary mosaic of the first example, the formulation ratio a / (a + b) was 1/11. For the exemplary mosaic of the fourth example, the formulation ratio (Si02 / (Ti02 + Al203 + Si02)) was 1/11. For the exemplary mosaic of the fifth example, the formulation ratio (Al203 / (Ti02 + Al203 + Si02)) was 1/11. Regarding the reference mosaic of a two-component system, the proportion by weight of the metal to Ti02 was 0.001 (Ag / Ti02) for the reference mosaic of a two-component system with silver formulated there and 0.01 (Cu / Ti02) for the reference mosaic of a two-component copper system formulated there. For these tiles, CNO / output and CN02 / output were measured using a test apparatus shown in Figure 4 in the same manner as described above in connection with evaluation test 1 in the first example. (CNO / input-CNO / output), CN02 / output and NOx reduction 30 minutes after the start of irradiation with light were determined from measured values of CNO / output and CN02 / output and the known test gas concentration ( CNO / entry). The results are summarized in Table 1.

Table 1 15 fifteen (CNO / input-CNO / output) represents the amount of NO oxidized to N02 or N03"(amount of NO reduced) and is a value indicative of NO's oxidizing activity CN02 / output represents the amount of N02 that has been released The lower the N02 / output, the higher the capacity to prevent N02 from being released outside the system, that is, the capacity to adsorb N02 will be higher, which is why, as shown in Table 1, the exemplary mosaic of the fourth example exhibits NO oxidation activity equal to or higher than for the first example and can achieve high NOx reduction.In particular, the exemplary mosaic of the fourth example with formulated silver had high (CNO / input-CNO / output) , ie, high NO oxidation activity and low CN02 / output, that is, high N02 adsorption activity.Thus, the exemplary mosaic of the fourth example had a combination of good oxidation activity with good adsorption activity. The results of the test for the reference mosaic show that support prior to photoreduction allows NO oxidation activity and NOx reduction, substantially equal to those in the first example, to be achieved even in the case of the two-component system of titanium dioxide and metal . As apparent from the test results for the exemplary mosaic of the fifth example, the silica formulation could provide NO oxidation activity and NOx reduction substantially equal to those of the first example, indicating that the silica formulation did not present associated problem with NOx reduction. In the fourth and fifth examples, with respect to titanium dioxide as the photocatalyst, the crystalline form can also be rutile or brookite. In addition, ZnO, V205 / W03 (Sn02? SrTi03, Bi203 and Fe203 can also be used as the photocatalyst.) When the gas to be reduced is an acidic gas, such as NOx, it is possible to use zinc oxide and tin oxide (as oxides of amphoteric metal), magnesium oxide, calcium oxide, rubidium oxide, sodium oxide and potassium oxide (as basic metal oxides) instead of alumina such as metal oxide.When the gas to be reduced is a basic gas, phosphorus oxide can be used (acidic metal oxide) in addition to amphoteric metal oxides. In addition, the above metals can be used instead of silver and copper and the above oxides can be used instead of silica. Next, the sixth and seventh examples will be described. As with the formulation of the fourth example, the formulation of the sixth example was of a system of four components comprising a combination of a photocatalyst typified by titanium dioxide, an amphoteric, basic or acidic metal oxide, typified by alumina, the metal previously described in connection with the fourth example, such as copper, silver, palladium, iron, nickel, chromium, cobalt, platinum, gold, rhodium or ruthenium and the other compound (oxide) described above in connection with the fourth example such as silica. The formulation of the seventh example was of a three component system comprising a combination of a photocatalyst, an amphoteric, basic or acidic metal oxide typified by alumina and the other compound (oxide) described above in connection with the fourth example, such as silica. The formulations of the sixth and seventh examples aimed at improving the decomposition activity including the decomposition of environmental contaminants such as NOx and to avoid contamination. As with the fourth example, in the sixth example, photocatalyst sols containing a photocatalyst (titanium dioxide), with plate or copper supported thereon, were dispersed there by simple mixing or support before photoreduction. As with the fourth example, the exemplary mosaic of the sixth example is prepared in the same manner as described above in connection with evaluation test 1 in the first example. As with the fifth example, the exemplary mosaic of the seventh example is prepared by mixing the photocatalyst sol with a sol of other ingredients (alumina and silica) stirring the mixture, spray-coating the mixed sun on the mosaic and baking the coated mosaic. Separately, in order to investigate the influence of additionally formulated silica and metal, mosaics (reference mosaics) were prepared for a two-component photocatalyst / metal system (silver or copper), a two-component system of photocatalyst / silica and a three component photocatalyst / metal (silver or copper) / silica system. In this case, by coating the photocatalyst sol on the substrate (mosaic), spin coating, dip coating or other coating means may be employed instead of the spray coating. The fixation of the photocatalyst sol on the surface of the substrate is carried out when burning or baking as used in the evaluation test 1 of the first example (baked type), or by mixing a silicone resin, with a photocatalyst sol and curing the silicone resin at a relatively low temperature (type of paint). The exemplary mosaics of the sixth and seventh examples, the reference mosaic and the comparative mosaic, were evaluated. The comparative mosaic used was the same as described above in connection with the evaluation test 1 in the first example.

The formulation ratio (Si02 / (Ti02 + Al203 + Si02)) for the exemplary mosaic of the sixth example was 1/10. The formulation ratio (Al203 / (Ti02 + Al203 + Si02)) for the exemplary mosaic of the seventh example was 1/10. The formulation ratio (Si02 / (Ti02 + Si02)) for the reference mosaic of a two-component photocatalyst / silica system was 1/5. Regarding the reference mosaic of the two-component photocatalyst / metal system, the weight ratio of the metal to Ti02 was 0.001 (Ag / Ti02) for the reference mosaic of a two-component system, with formulated silver and 0.01 (Cu / Ti02) for the reference mosaic of a two-component system with formulated copper. For the reference mosaic of the three-component photocatalyst / metal / silica system, the weight ratio of metal to Ti02 was the same as in the reference mosaic (0.001 (Ag / Ti02) and 0.01 (Cu / Ti02)), and the formulation ratio (Si02 / (Ti02 + Si02)) was 1/5. Initially, in order to investigate the influence of additionally formulated metal, the reference mosaics of a two-component photocatalyst / metal system (silver or copper) will be described. For the reference mosaics of the two-component system in the case of the baked type, various metal salts (special grade reagent, manufactured by Wako Puré Chemical Industries, Ltd.) were formulated in a titanium oxide sol (STS-11, manufactured by Ishihara Sangyo Kaisha Ltd.). The metal salt was formulated in an amount of 0.001 to 10% based on titanium oxide (on a solid base) in the titanium oxide sol. Subsequently, silver or copper was supported in the photocatalyst by simple mixing, support before photoreduction or co-precipitation. On the support before photoreduction, after an aqueous solution of metal salt, this is a silver or copper salt mixed with the sun titanium oxide, the mixture is exposed to ultraviolet light at an intensity of 1 mW / cm2 per 2 hours. In this way, a sun was prepared. of the photocatalyst with the metal supported on it. In the case of coprecipitation, a TiOS04 solution is provided as a starting compound and an aqueous metal salt solution is added to this solution, followed by hydrolysis to prepare a photocatalyst sol with the supported metal therein. Subsequently, these photocatalyst sols were spray-coated on the surface of the mosaic to give a coating having a thickness of about 0. 8 μm in terms of thickness after burning. The coated mosaics were burned from 600 to 900 ° C (approximately 800 ° C for the reference tiles) to obtain reference mosaics of the two-component system (baked type).

In the case of paint type, various metal salts (special grade reagent, manufactured by Wako Puré Chemical Industries, Ltd.) were formulated in a titanium oxide sol (TA-15, manufactured by Nissan Chemical Industries Ltd.). The metal salt is formulated in an amount of 0.001 to 1% based on titanium oxide (on a solid basis) in the sun titanium oxide. Subsequently, the photocatalyst sol with silver or copper supported there by simple mixing or support before photoreduction and a silicone resin as a binder, were mixed together at a ratio of solids content of titanium oxide to silicone resin of 7.3. The mixtures were coated by centrifugation on the mosaic surface and the coated mosaics were heated to 150 ° C to obtain the reference mosaics of the two-component system (paint types). The reference mosaics of the two-component system (baking type and paint type) were evaluated for the decomposition activity of chemical material. The decomposition activity can be evaluated directly in terms of antimicrobial activity and oil decomposition. In this case, the antimicrobial activity is evaluated in terms of growth inhibitory / killing activity against Escherichia coli W3110 as described above in the third example. In this case, the antimicrobial activity of the mosaic having a photocatalyst layer formed of a photocatalyst (titanium dioxide) was only taken as 1. The decomposition of oil is determined as follows. A salad oil was coated on a sample at a coverage of 1 mg / 100 cm2 and the coated sample was irradiated with ultraviolet light at an intensity of 1 mW / cm2 for 7 days. The brightness of the sample was measured before the oil coating, immediately after the oil coating and at the end of the irradiation. The decomposition of oil was determined according to the following numerical formula. Decomposition of oil (%) = [. { (Brightness at the end of irradiation) - (Brightness immediately after oil coating)} /. { (Gloss before oil coating), (Gloss immediately after oil coating)} ] x 100. The decomposition of chemical materials by a photocatalyst is derived primarily from the oxidation of chemical materials with active oxygen species released from the photoexcited photocatalyst. Therefore, the oxidation activity of the photocatalyst can be used as an index of one of the activities of the photocatalyst to break down chemical materials. Here, the NO oxidation activity of various thin photocatalyst films was also evaluated in terms of the conversion of nitrogen monoxide (NO) to nitrogen dioxide (N02) by oxidation as a model reaction. In order to determine the oxidation activity of NO, CNO / output is measured using a test apparatus shown in Figure 4, in the same manner as described above in connection with the evaluation test 1 of the first example. (CNO / input - CNO / output) is determined against the time elapsed after light irradiation from CNO / measured output and the known test gas concentration (CNO / input), and the total number of moles of NO, which has been oxidized in a period between the onset of light irradiation and one hour after the start of light irradiation, is calculated from (CNO / input - CNO / output) and considered as the oxidation activity of NO. In this case, the NO gas flow (test gas) was 2 liters / minute, and the sample piece had a size of 5 x 50 cm2. For the reference mosaics (baked type and paint type) of the two-component system, the antimicrobial activity, the decomposition of oil and the oxidation activity of NO are summarized in Table 2. As is apparent from the previous description, the activity antimicrobial, the oil decomposition and the oxidation activity of NO shown in Table 2 were measured in such a way that the mosaics were placed under light conditions.

Table 2: Part 1 Evaluation of decomposition activity for baked type reference mosaics Table 2: Part 2 Evaluation of decomposition activity for paint type reference mosaics From Table 2, it is apparent that, for a system loaded with copper in baked type reference mosaics, mosaics with 1% copper supported on Ti02 prepared by supporting before photoreduction had the best antimicrobial activity, oil decomposition and oxidation activity not. Also, for a system loaded with silver, the support before photoreduction instead of simple mixing had the best antimicrobial activity, oil decomposition and NO oxidation activity. For addition of any metal in the table, all the antimicrobial activity, the decomposition of oil and the oxidation activity of NO were superior to those in the system without metal loading, indicating that metals such as copper, silver, palladium and iron supported on Ti02 contribute to an improvement in Ti02 decomposition activity. For a system loaded with copper type baking, mosaics with 0.1 to 1% copper supported on Ti02 prepared by supporting before photoreduction had the highest antimicrobial activity. In addition, it was found that the silver loaded system had superior antimicrobial activity than the copper loaded system. From the above results, it is noteworthy that for reference-type baked tiles and reference mosaics such as paint, supporting metals such as copper, silver, palladium and iron in Ti02 can improve the decomposition activity. That is, the above metals clearly have the function of improving the decomposition activity of Ti02. In addition, for the metal support method, the support prior to photoreduction is superior in the simple mixed decomposition activity. In addition, the regulation of the amount of metal supported can vary the decomposition activity of Ti02. The antimicrobial activity of reference-type baking mosaics of two-component system, when placed under dark conditions was also investigated. As a result, for a reference mosaic with 0.1% copper supported on Ti02 by simple mixing, the antimicrobial activity was approximately 0.3. Also for a reference mosaic, 1% copper supported on Ti02 by simple mixing, the antimicrobial activity was approximately 0.3. Also, for a reference mosaic with silver 0.1% supported between them two by simple mixing, the antimicrobial activity was approximately 0.3. Under dark conditions, since the photocatalyst is not activated, the antimicrobial activity of the reference mosaic is provided by the metal supported per se. When the fact that the antimicrobial activity of the mosaic without metal loading, that is, the mosaic that the photocatalyst uses is only substantially zero is taken into consideration, it can be said that, under light conditions, the antimicrobial activity of these reference mosaics it exceeds the antimicrobial activity of the metal per se and the antimicrobial activity of the mosaic using the photocatalyst alone (1 of Table 2). For example, the antimicrobial activity of the reference mosaic with 0.1%, copper supported on Ti02 by simple mixing is 1.5 of Table 2. This value exceeds the sum of the antimicrobial activity (0.3) copper per se and the antimicrobial activity (1) of the mosaic using the photocatalyst alone. Therefore, it can be said that the support copper in Ti02 can provide greater effect than a simple combination of copper with Ti02. Based on the above effect of the reference mosaics, the exemplary mosaics of the sixth and seventh examples will be described. In the sixth and seventh examples, hydrophilicity was also evaluated, which is an additional evaluation item. At the beginning, before the hydrophilicity test and other tests, the relationship between the hydrophilicity and the incrustation of the surface will be described. In recent years, it has been found that imparting hydrophilicity to the surface can prevent surface fouling (Kobunshi (Polymer), Vol. 44, May, 1995, p.307). Hydrophilicity can be expressed in terms of the contact angle of the surface with water. The smaller the contact angle, the better the wettability of the surface by water. In this case, water, which has come into contact with the hydrophilic surface, is less likely to remain on the contact surface. When water is less likely to remain in contact with a surface, pollutants such as city dust, rainwater content and the like, along with water, run off from the hydrophilic surface to improve the effect of preventing fouling. For this reason, a proposal has been made to coat a graft polymer with hydrophilicity imparted on exterior walls of buildings and the like in order to avoid embedding of the walls by the graft polymer coating. Since, however, the hydrophilicity of the graft polymer coating in terms of the contact angle of the graft polymer coating with water is approximately 30 to 40 °, the water has to relatively remain on the surface. Therefore, the anti-fouling effect and the anti-fogging effect are not necessarily satisfactory. The inorganic powder typified by the clay mineral has a contact angle with the water of about 20 to 50 ° and therefore has affinity for the graft polymer having the above contact angle and is likely to be deposited on the surface of the graft polymer. This also makes it difficult for the coating and the graft polymer film to exhibit the effect of highly preventing the surface from embedding itself particularly with inorganic powder. When the contact angle becomes smaller than that of the inorganic powder, such as city powder having a high content of lipophilic component and clay minerals, the anti-fouling effect can be further improved without affinity of the powder by the surface of the substrate As the contact angle approaches 0 °, the hydrophilicity increases and the water probably diffuses into a film form and probably flows on the substrate surface, not only allowing the city dust but also the inorganic powder together with water, runs off easily on the surface of the substrate. In this case, the contact angle more preferably is not greater than about 20 ° and is close to zero from the viewpoint of improving the anti-fouling effect. Based on the above problem, the exemplary mosaics of the sixth and seventh examples of the present invention using a photocatalyst have been studied.

Since the hydroxy OH radical is produced by the catalytic reaction of the photocatalyst, the contact angle of the mosaics with water, which is an indication of hydrophilicity, was measured. The test will be summarized below. Sample pieces having a convenient size (baked type) of the exemplary mosaics of the sixth and seventh examples, the reference mosaics of the two-component system and the three-component system and the comparative mosaics as described above, were provided. The contact angle of a droplet of water in the sample piece was measured after application of ultraviolet light (wavelength: 320 to 380 nm, amount of light received by the sample piece: approximately 1 mW / cm2) from a Ultraviolet irradiation lamp for approximately 24 hours (under light conditions) before mosaic production and after the sample piece was placed in a dark place for a period of time long enough to substantially completely stop the activity of the sample. photocatalyst (under dark conditions). The measurement results are summarized in Table 3.

Table 3 Type Baking From the results shown in Table 3, it is apparent that, as with the reference mosaics of the two-component system that have been examined for the influence of the metal formulation, for the exemplary mosaics of the four-component system (sixth example) The formulation of metals indicated in the Table, such as copper and silver, can improve all the antimicrobial activity, the oil decomposition activity and the oxidation activity of NO and improve the decomposition activity. In addition, exemplary mosaics can provide the antimicrobial activity exceeding the sum of the antimicrobial activity of the metals indicated in the table, such as copper and silver per se and the antimicrobial activity of the comparative mosaic using the photocatalyst alone and the exemplary mosaics of the three components. In addition, the Mohs hardness of the surface layer is equal to that of a simple mosaic that has no surface layer, indicated that the exemplary mosaics of the sixth example can be put into practical use as the mosaic. The contact angle of the exemplary mosaics of the sixth and seventh examples is less than the comparative mosaic regardless of whether the mosaics are placed under light conditions or under dark conditions, indicating that, as previously described, Si02 or A1203, already either alone or in combination, formulated together with Ti02 can contribute to an improvement in hydrophilicity of the mosaic surface through adsorption of the hydroxyl group. It was also found that the formulation of the metals indicated in the table, such as copper and silver, does not cause an increase in the contact angle, that is, a reduction in hydrophilicity, of these facts, it is apparent that thin functional films that have Both decomposition activity and hydrophilicity and functional materials having these thin films can be produced through metal supports that contribute to the improvement of decomposition activity, such as copper, silver, palladium, iron, nickel, chromium, cobalt, platinum, gold, rhodium and ruthenium, on Ti02 and formulations of Si02 and Al203, which contribute to an improvement in hydrophilicity, either alone or in combination in Ti02. Of course the exemplary mosaics of the sixth and seventh examples have the effect of reducing the noxious materials, such as nitrogen oxides, as described in the first and second examples, because the surface layer contains Al203, in addition to Ti02. The exemplary mosaic of the seventh example of the three component system free of the above metal, has NO oxidation activity equal to the comparative mosaic. For the exemplary mosaics of the sixth and seventh examples, however as described above in connection with the first and second examples, N02 is also reduced because the intermediate (N02) is chemically converted to nitric acid. Therefore, the exemplary mosaic of the sixth and seventh examples has the effect of reducing all harmful materials including NO and N02. The effect of improving the decomposition activity is examined for the exemplary mosaics of the sixth and seventh examples (painting type). The results were as summarized in Table 4. The results show that, also for the type of paint, according to the exemplary mosaics of the sixth and seventh examples, the formulation of the metals indicated in the table can improve all the activity antimicrobial, the activity of oil decomposition and the oxidation activity of NO and can improve the decomposition activity. It is, of course, that with exemplary baked-type mosaics, the exemplary paint-like mosaics of the sixth and seventh examples may contribute to an improvement in hydrophilicity of the mosaic surface through adsorption of the hydroxyl group derived from Si02 which has been formulated together with Ti02. Also for exemplary paint type mosaics, the surface layer has a 4H pencil hardness, indicating that exemplary paint type mosaics can be put into practical use as mosaics.

Table 4 Painting type The amount of copper, silver and the like formulations will be described by taking the exemplary mosaics of the sixth example of the four component photocatalyst / metal / alumina / silica system, as an example. The exemplary mosaics of the sixth example were such that the formulation ratio (Si02 / (Ti02 + Al203 + Si02)) was constant and 1/10 with the proportion of metal formulation c / d varied where c represents the weight of the metal and d represents the weight of Ti02. For exemplary mosaics, the relationship between the proportion of metal formulation and the antimicrobial activity is examined. The results are shown in Figure 11 (baked type) and Figure 12 (paint type). In this case, the antimicrobial activity is expressed by taking the antimicrobial activity of the exemplary mosaic of the seventh example of the three component photocatalyst / alumina / silica system as 1. As is apparent from Figures 11 and 12, both for the baked type, As the paint type, an antimicrobial activity of not less than 1 can also be provided in the case of any metal of silver, palladium, platinum, copper and chromium, when the proportion of metal formulation was not less than about 0.001. The antimicrobial activity peaked when the proportion of metal formulation was approximately 0.001 for silver, palladium and platinum and approximately 0.01 for copper and chromium. After the antimicrobial activity reached its maximum, it gradually decreased. This demonstrates that satisfactory results can be achieved when metals such as silver, palladium, platinum, copper and chromium are formulated in a metal formulation ratio of about 0.00001 to 0.05. That is, when these metals are formulated in a proportion of metal formulation not less than 0.00001, advantageously there is no possibility that the metal does not contribute to an improvement in antimicrobial activity in fact due to an excessively small metal content. On the other hand, when these metals are formulated in a formulation ratio not higher than 0.05, advantageously, there is no possibility that the amount of metal is excessive in relation to the amount of photocatalyst (Ti02), adversely affecting the catalytic reaction of photocatalyst . It was further found that exemplary mosaics having a surface layer containing silver, palladium or platinum as the fourth component, have superior antimicrobial activity with exemplary mosaics having a surface layer containing copper or chromium as the fourth component. Surface properties of the surface layer formed on the surface of the mosaic using the photocatalyst sol as described above, will be described by taking the exemplary mosaic of the sixth example of the photocatalyst / metal / alumina / silica four-component system and the exemplary mosaic of the seventh example of the three component photocatalyst / alumina / silica system as an example. In this case, the exemplary mosaics of the sixth and seventh examples were such that, in the surface layer, the formulation ratio (Si02 / (Ti02 + Al203 + Si02)) was constant and 1/10 with the thickness of the layer superficial, one of the superficial properties, is varied. For exemplary mosaics, the relationship between the surface layer thickness and the contact angle, the antimicrobial activity, the oil decomposition activity or the NO oxidation activity are examined. The results are shown in Figures 13 to 17. Figures 13 to 16 show the results for the exemplary tiles (baked type) of the sixth example of the four component system. Specifically, Figure 13 is a graph showing the relationship between the surface layer thickness and the contact angle under light conditions, Figure 14 is a graph showing the relationship between the surface layer thickness and the antimicrobial activity, Figure 15 is a graph showing the relationship between the surface layer thickness and the oil decomposition activity, and Figure 16 is a graph showing the relationship between the surface layer thickness and the NO oxidation activity. In this case, the antimicrobial activity is expressed by taking the antimicrobial activity of the mosaic having a surface layer containing photocatalyst / alumina / silica as 1. Figure 17 is a graph showing the relationship between the thickness of the surface layer and the angle of contact under light conditions of the exemplary mosaics (baked type) of the seventh example of the three-component system. The exemplary mosaics of the four-component system had a surface layer containing silver, palladium, platinum, copper or chromium, the surface layer having a thickness of 0.005 to 3 μm. For the exemplary mosaics of the three-component system and the four-component system as described above, since the surface layer contains SiO2, which can contribute to an improvement in hydrophilicity through adsorption of a hydroxyl group, the function exerted by The incorporation of Si02 (improved hydrophilicity) is expected. In this case, as described above, the improvement in hydrophilicity is confirmed based on whether or not the contact angle is small, and a contact angle not greater than 20 ° is preferred. When Figures 13 to 17 are observed when taking this into consideration, it is apparent that for the baked type of the exemplary mosaics of the three-component system and the four-component system, a constant low angle no greater than 20 ° is provided when the surface layer thickness is not less than about 0.01 μm, that is, the anti-fouling effect can be advantageously achieved through improved hydrophilicity. The reason why the low contact angle not greater than 20 ° is provided in the case of a surface layer thickness of not less than about 0.01 μm is considered to lie in that, by virtue of the satisfactory layer thickness (surface layer) the contact angle of the surface layer formed in the substrate (mosaic) per se can be provided even when the contact angle of the substrate is large. As apparent from Figures 13 and 17, when the surface layer thickness is not less than about 0.5 μm, the contact angle is kept low. On the other hand, the weight per contact area of the surface layer increases with increasing surface layer thickness. Therefore, when the surface layer thickness is excessively large, the adhesion between the substrate and the surface layer is often reduced, causing the surface layer to be separated. For this reason, the surface layer thickness is preferably not greater than about 3 μm from the viewpoint of maintaining adhesion between the substrate and the surface layer. Further, when the surface layer thickness is excessively large, the ultraviolet light does not reach the lower portion of the surface layer in fact. This makes it impossible for the entire part of the surface layer to exhibit the photocatalytic activity. Also, from this point of view, the surface layer thickness is preferably not greater than about 3 μm. As illustrated in Figures 14 to 16, when the surface layer thickness is in the previous range (approximately 0.01 to approximately 3 μm), advantageously the antimicrobial activity, the oil decomposition activity and the oxidation activity of NO can surely be improved. In addition to the surface layer thickness, the following surface properties were also investigated. Before ultraviolet irradiation, excitation electrons together with hydroxyl radicals are produced by the photocatalyst. Therefore, specific phenomena created in the surface layer by excitation electrons and state inspection can reveal how the excitation electrons are produced, that is, how the hydroxyl OH radicals are produced. For the exemplary mosaics of the sixth and seventh examples, the surface layer contains Si02 which can adsorb and retain a hydroxyl group, such that the hydroxyl OH radicals produced by the photocatalyst are retained in SiO2. Therefore, it is considered that a large amount of excitation electrons produced by the photocatalyst result in a production of a greater amount of hydroxy OH radicals and consequently improves the hydroxyl density at the surface of Si02 and reduces the contact angle with water , improving hydrophilicity. For this reason, when ultraviolet radiation is carried out with silver nitrate solution deposited in the surface layer, the charge of the silver ion in the silver nitrate solution deposited in the surface layer is varied by excitation electrons to develop a reaction color. This creates a difference in color between before ultraviolet irradiation and after ultraviolet irradiation. This difference in color? E is increased by increasing the number of excitation electrons involved in the reaction and therefore can serve as an indication of hydrophilicity. Therefore, the color difference? E is observed as follows. For the measurement of the color difference? E, a solution of 1% silver nitrate, a general reagent capable of developing a color reaction, is employed. Silver ions contained in this solution are precipitated as silver as a result of a reaction with excitation electrons (e ~) produced by the photocatalyst according to the following formula. The precipitation of silver causes the color on the surface deposited with silver nitrate solution to change to brown or black, creating a clear color difference? E. Ag + + e "? Ag I Therefore, a 1% silver nitrate solution is deposited on the surface layer of the painting type of exemplary mosaics of the sixth example (four components) and the seventh example (three components) and on In this state, the exemplary mosaics were irradiated with ultraviolet light, followed by measurement of the color difference? E for each of the mosaics.The ultraviolet light is applied at an intensity of 1.2 mW / cm2 in the surface layer for 5 minutes, and the relationship between the measured color difference? E and the contact angle, the antimicrobial activity, the oil decomposition activity or the NO oxidation activity was investigated.The results are shown in Figures 18-22. measurement of the color difference? E, the residual aqueous solution on the surface of the mosaic is wiped with a Kim towel, and the difference in the amount of development or development of silver color of the mosaic surface between this state and before testing (before ultraviolet irradiation) is determined. The amount of development or development of color is measured with a color difference meter ND300A manufactured by Nippon Denshoku Co., Ltd. According to JIS Z 8729 (1980) and JIS Z 8730 (1980). Figures 18 to 21 show the test results for the exemplary mosaics (paint type) of the sixth example of the four component system. Specifically, Figure 18 is a graph showing the relationship between the color difference? E and the contact angle under light conditions, Figure 19 is a graph showing the relationship between the color difference ΔE and the antimicrobial activity, Figure 20 is a graph showing the relationship between the surface layer thickness and the oil decomposition activity and Figure 21 is a graph that shows the relationship between the color difference? E and the oxidation activity of NO. Also, in this case, the antimicrobial activity is expressed by taking the antimicrobial activity of the mosaic having a surface layer containing photocatalyst / alumina / silica as 1. Figure 22 is a graph showing the relationship between the color difference? and the contact angle under light conditions in the exemplary mosaic (paint type) of the seventh example of the three-component system. The exemplary mosaics of the four-component system had a surface layer containing silver, and the test was carried out for mosaics that provide color differences? E in the range of 0 to 60. In this case, the mosaic that provides a color difference? E from zero was a simple mosaic that does not produce excitation electrons (a mosaic that has a surface layer formed of paint only). As apparent from Figures 18 and 22, a color difference ΔE of not less than 1 is preferred because the contact angle is as low as no greater than 20 ° and the anti-fouling effect is improved through the improved hydrophilicity. When the color difference? E is not less than about 10, the contact angle remains low. On the other hand, the greater the quantity of photocatalyst, the more active the production of excitation electrons and the greater the difference in color? E. In this case, however, the amount of photocatalyst based on the total amount of ingredients other than the photocatalyst (Al203, Si02, or a combination of Al203 or Si02 with the previous metal) becomes large, and a larger amount of photocatalyst reduces Adhesion to the substrate and creates a greater tendency to the separation of the surface layer. When the color difference? E is not greater than 50, the amount of photocatalyst based on the total amount of other ingredients to the photocatalyst is not excessively large, which can advantageously avoid the separation of the surface layer. As illustrated in Figures 19 to 21, the color difference? E is preferably in the above range (about 1 to about 50) from the viewpoint of surely improving the antimicrobial activity, the oil decomposition activity and the NO oxidation activity. Next, an improvement in superhydrophilic activity that is achieved by the addition of other ingredients (metal oxides) that contribute to an improvement in hydrophilicity of Ti02, such as Si02 or Al203, will be described. Exemplary baking type mosaics of the eighth example will be described first. (i) Photocatalyst and metal oxide sol supply: photocatalytic material / Sol Ti02: average particle diameter approximately 0.02 μm (STS-11, manufactured by Ishihara Sangyo Kaisha Ltd.) or average particle diameter of approximately 0.01 μm (A-6L, manufactured by Taki Chemical Co. , Ltd.). Sol Sn02: average particle diameter approximately 0.002 μm (manufactured by Taki Chemical Co., Ltd.).

In the eighth example, sol Sn02 is also used in the anatase form of Ti02 sol which is harmless, chemically stable and economical. Other Ti02, SrTi03, ZnO, SiC, GaP, CdS, CdSe, MoS3, V205, W03, Sn02, Bi205 and Fe203, photocatalytically active crystals, can be used as alternative materials. Metal oxide / sol Si02: average particle diameter approximately 0.007 to approximately 0.009 μm (Sno tex S, manufactured by Nissan Chemical Industry Ltd.). Sol Al203: average particle diameter approximately 0.01 μm x approximately 0.1 μm (Alumina Sol 200, amorphous form, manufactured by Nissan Chemical Industry Ltd.) or average particle diameter approximately 0.01 to approximately 0.02 μm (Alum 520 Sol, boehmite form, manufactured by Nissan Chemical Industry Ltd.). Sol Si02 + K20: (Snowtex K, Si02 / K20 molar ratio 3.3 to 4.0, manufactured by Nissan Chemical Industry Ltd.). Sol Si02 + Li02: (Lithium silicate 35, molar ratio of Si02 / Li02 3.5, manufactured by Nissan Chemical Industry Ltd.). Sol Zr0: average particle diameter approximately 0.07 μm (NZS-30B, manufactured by Nissan, Chemical Industry Ltd.).

All the above salts were commercially available products. Alternatively, it is possible to use a liquid prepared by adding a hydrolysis inhibitor, such as hydrochloric acid or ethylamine, to a metal alkoxide as the starting material, diluting the mixture with an alcohol, such as ethanol or propanol, and allowing that hydrolysis is partially or totally carried out.

For example, titanium alkoxides usable herein include tetraethoxytitanium, tetraisopropoxytitanium, tetra-n-propoxytitanium, tetrabutoxytitanium and tetramethoxytitanium.

In addition, other organometallic compounds (chelates and acetates) and inorganic metal compounds, such as TiCl4 and Ti (S04) 2, can be used as starting material. (ii) Preparation of materials imparting hydrophilicity: In the mixing of a sol of the photocatalytic material with a sol of the metal oxide, each of the sols was previously diluted to give a solids content of 0.4% by weight and the sols were mixed together in proportions as indicated in Table 5 below, followed by complete stirring. The proportion by weight is solid after mixing is the weight ratio of liquid of the sols. (iii) Preparation of mosaics made hydrophilic: An enameled or glazed mosaic (AB06E11, manufactured by TOTO) is provided with the substrate, and a predetermined amount of the mixed sol is spray coated on the mosaic surface at a layer thickness of approximately 0.5 μm. The coated substrate is burned at a maximum temperature of about 700 to 900 ° C in a rolling crucible furnace (RHK = Roller Hearth Kiln) for a burn time of 60 minutes. In this way, the exemplary mosaic of the eighth example occurs. In the eighth example, spray coating was used. In addition, flow coating, spin coating, dip coating, roller coating, brush coating and other coating methods are usable. In the eighth example, mosaics were used as the substrate. In addition to mosaics, metals, ceramics, ceramics, crystals, plastics, wood, stones, cements, concretes or combinations or laminates of the previous substrates, they can be used. In this eighth example, the suns used were those described in the previous suns, that is, they were of a two- or three-component system of a combination of the photocatalyst, the amphoteric or basic metal oxide or acidic typified by alumina, and the other compound (oxide) such as silica, described in the fourth example. In some cases, however, as illustrated in Table 5, a plurality of the compound types (metal oxides) can be employed as a component. (iv) Evaluation: Hydrophilicity was evaluated in terms of the static contact angle of the water. At the exit, test tiles (the mosaic of example eight and the comparative mosaic) were irradiated with ultraviolet light from a BLB fluorescent lamp (a black light lamp, FL20BLB, manufactured by Sankyo Electric Co., Ltd.) at an intensity of 1.5 mW / cm2 for 24 hours and the contact angle of the mosaics with water was then measured. Subsequently, the mosaics were stored under protected conditions against light (in a dark place) for 72 hours and the contact angle with water was measured again. The results are summarized in the table. The film strength is evaluated in terms of Mohs hardness. The results are summarized in Table 5.

Table 5 15 Table 5 (Continued) 15 As is notable from Numbers 2 to 14 of Table 5, in the production of hydrophilicity by ultraviolet irradiation, when Ti02 / (Ti02 + Si02 + Al203) > . 0.4, the contact angle of the exemplary mosaics with water is not greater than 10 °, indicating that a satisfactory quality of hydrophilicity was achieved. After storage in a dark room, when the amount of Ti02 is identical, the hydrophilicity is maintained at a higher level by increasing the amount of Al203 added. In addition, when Si02 is added, the hardness is increased by increasing the amount of Si02 added. From these facts, it is remarkable that the addition of Si02 and A1203 to the photocatalyst (Ti02) can provide a formulation which, compared to the photocatalyst alone, has better hydrophilicity under light irradiation conditions has improved retention of hydrophilicity under dark conditions and It was found to have improved hardness and coating density. When using sols described in this example, it is considered that, among these effects, the improved hydrophilicity is provided primarily by the addition of Al203 and the improved film hardness is provided by the addition of SiO2. No. 1 in Table 4 shows the results of enameled or glazed mosaics, while No. 2 shows the results by the mosaic using the photocatalyst alone (comparative mosaic).

Nos. 15 to 18 in Table 5 show the results of the same mosaics used previously, except that a part of Si02 is replaced with K20. Also in this case, the improved hydrophilicity and the increased layer hardness have been achieved in the burning temperature range from about 700 to about 800 ° C by the addition of Si02, K20 and Al203. No. 19 shows the results of the test in which a part of Si02 has been replaced with Li02. Also in this case, hydrophilicity and layer hardness have been improved. No. 17 and No. 18 show the result of an examination in the form of starting material for the alumina sol. The use of an alumina sol, which is amorphous and has a pen-like structure, was found to further improve hydrophilicity. This suggests, that in order to improve hydrophilicity, the structure having higher hydrophilic group content is more effective than the particle form. No. 20 shows the results of the test where Zr02 has been added to Ti02. From these facts, it is apparent that Zr02 is also effective in improving hydrophilicity. No. 21 and No. 22 show the results of the test where Sn02 has been employed as the photocatalyst.

It was confirmed that the use of Sn02 alone can also provide hydrophilic effect and further addition of Al203 can provide improved hydrophilicity. At this time, the layer hardness was not reduced and it was confirmed that Sn02 per se had the function of the binder. In addition, as apparent from No. 3 and No. 14, the greater the amount of Al203 added, the lower the contact angle and the better the hydrophilicity. Therefore, hydrophilicity can be varied by regulating the amount of Al203 added. From the results shown in Table 2, since the decomposition activity of Ti02 can be varied by regulating the amount of metals, such as copper, silver, palladium and iron supported in the photocatalyst, regulating the amount of Al203 added and the Regulation of the supported metal can compensate the balance between hydrophilicity and decomposition activity (decomposition properties). As a result, when high decomposition activity is required, the high decomposition activity required can be achieved while maintaining the level of hydrophilicity equal to or higher than the level reached by the photocatalyst. Having both the hydrophilic nature and the decomposition activity has the following advantages. Specifically, a two step stain removal process based on the hydrophilic nature and stain removal based on the decomposition activity can provide a markedly improved removal of deposited stains and improved removal rate. In this case, for some spots, the strength of deposition of light spots that remain after the removal of stains based on the hydrophilic nature is high. However, the improved decomposition activity through the regulation of the amount of metal supported allows even slight spots to have a high deposition force to be removed. In addition, the removal of the stain can prevent the photocatalyst from being subjected to light protection. This can increase the amount of light applied. Therefore, the removal of stains based on the hydrophilic nature and removal of stains based on the decomposition activity, can be retained very efficiently. In summary, it was found that the addition of Si02, Al203 or Zr02 to the photocatalyst can improve the contact angle under light irradiation conditions and retention of hydrophilicity after storage in a dark place. This effect is considered created by the hydrophilic nature of these materials. The heat of wetting can be mentioned as indicative of the hydrophilicity of materials. The wet heat of Ti02, a preferred photocatalyst, is 320 to 512 x 10"3 Jm" 2 for the anastase form and 293 to 645 x 10"3 Jm" 2 for the rutile form. For this reason, compounds having a heat of wetting not less than 500 x 10"3 Jm" 2 are preferred. In addition to the three previous metal oxides Ge02, Th02, and ZnO can be used. These metal oxides may be in crystalline form as well as in an amorphous form. Its particle diameter is not greater than 0.1 μm. The addition of Si02 is found to contribute to improved layer hardness. The replacement of a part of the amount of Si02 added with K20 or Li02 can improve the layer hardness even when the burning temperature is low. In particular when Ti02 / (content of total solid of regulating agent / imparting hydrophilicity) >; 0.5 and Si02 / (total solids content of regulating agent / imparting hydrophilicity) < .0.5 is satisfied, the previous effect can be expected. Next, an improvement in superhydrophilic activity by the addition of another ingredient (metal oxide) which contributes to an improvement in the hydrophilicity of Ti02 such as Si02 or Al203, and an improvement in other functions (improvement in layer hardness) will be described. for a painting type example (ninth example). (i) Provide metal dioxide and photocatalyst sols: Sun of photocatalytic material / Ti02: (TA-15, manufactured by Nissan Chemical Industry Ltd.). Also in this ninth example, a Si02 sol is used in addition to the sun anatase form Ti02 which is harmless, chemically stable and economical. Other Ti02, SrTi03, ZnO, SiC, GaP, CdS, CdSe, MoS3, V205, W03, Sn02, Bi205 and Fe203, crystalline photocatalytically active can also be used as alternative materials. Metal oxide sol / Ti02: (Glasea T2202, manufactured by Japan Synthetic Rubber Co., Ltd.). Sol Al203: average particle diameter of about 0.01 to about 0.02 μm (Alumina Sol 520, boehmite form, manufactured by Nissan Chemical Industry Ltd.). Ti02 employee was a commercially available product. A film-forming element comprising a silicone (an organopolysiloan) or a precursor of a silicone can also be used. Also for the Ti02 and Al203 sols, commercial products were used. However, as with the eighth example, these sols can be provided through the above steps, for example the addition of a hydrolysis inhibitor, such as hydrochloric acid or ethylamine, to an alkoxide of a metal as a starting material. (ii) Preparation of hydrophilicity imparting materials: The above starting materials were mixed in a given proportion as a whole. The mixture was diluted three times with ethanol to prepare a coating liquid. The coating liquid formulation was as follows. Table 6 UNCLE, SiO, A1203 1 1/10 0 to 1/12 1 1/5 0 to 3 1 1/2 0 to 3 1 1 0 to 3 1 2 0 to 3 1 5 0 to 3 (iii) Preparation of mosaics with hydrophilicity capability: As with the eighth example, a glazed mosaic is provided as a substrate, and the coating liquid was spin coated onto the substrate. The coated substrate was heated at 150 ° C for 30 minutes to cure the coating. Although the spin coating is employed in the ninth example, flow coating, spray coating, dip coating, roller coating, brush coating and other coating methods are usable. Also, in the ninth example, in addition to mosaics, metals, ceramics, ceramics, glass, plastics, wood, stones, cements, concretes or combinations or laminates of the previous substrates can be used as substrates. In this ninth example, the sols employed were those described above in connection with providing the sols, and as specified in Table 6, the ingredients were Ti02, Si02 and optionally Al203. Therefore, the surface layer is of a two or three component system of a combination of the photocatalyst, the amphoteric or basic or acidic metal oxide typified by alumina and the other compound (oxide) such as silica, described in the fourth example . (iv) Evaluation: For layer hardness, a pencil hardness test (General Test for Paints specified in JIS K 5400) was carried out for test tiles (the mosaics of the ninth example and the comparative mosaic). The results are summarized in Table 7. For hydrophilicity, the static contact angle with water is measured for the test tiles (the mosaics of the ninth example and the comparative mosaic) in the same way as in the eighth example. The results are summarized in Table 8. In this case, the intensity of ultraviolet irradiation was approximately 1.2 mW / cm2, and the ultraviolet irradiation time was 12 hours. or L? rH As is apparent from Table 7, when Si02 / Ti02 is not more than 0.1, the amount of binder, (sol Si02) is unsatisfactory, which leads to a reduced layer strength or strength. Furthermore, as is notable from Table 8, when Al203 / Ti02 is 1/12 to 2 with Si02 / Ti02 is 1/5 to 2, the effect of improving the hydrophilicity by the addition of alumina is developed. As described in the eighth example, this effect is also considered to be created by the hydrophilic nature of Al203. The heat of wetting can be mentioned as an indication of the hydrophilicity of materials. The heat of humidification of Ti0, a preferred photocatalyst is 320 to 512 x 10"3 Jm" 2 for the anatase form and 293 to 645 x 10"3 Jm" 2 for the rutile form. For this reason, compounds having a wetting heat of not less than 500 x 10"3 Jm" 2 are preferred. Also in this example, in addition to the three previous metal oxides Zr02 / Ge02, Th02 and ZnO can be used. These metal oxides may be in a crystalline form, as well as in an amorphous form. The present invention has been described with reference to the examples, but of course the present invention is not limited to the above examples and embodiments and various variations and modifications are made within the scope of the subject matter of the present invention.

For example, when anchoring copper particles, an oxide thereof or the like on a mosaic to produce a mosaic having supplemented antimicrobial activity, a method can be employed which comprises previously producing a mosaic having a surface layer and a photocatalytic formulation through coating a Ti / Al sol on the surface of a mosaic and burning the coated mosaic, and then coating a third sol on the surface layer of the mosaic followed by burning.

Claims (36)

1. CLAIMS 1.- A photocatalytic formulation comprising: a photocatalyst that functions as a catalyst when exposed to light; and another compound, characterized in that, when a reagent is applied to the catalytic reaction, in which the photocatalyst participates, it is catalytically reacted and converted chemically to a final product specified by the reagent structure and the catalytic reaction, the other compound functions in the co-presence of the photocatalyst to improve the conversion of the reactant to the final product.
2. 2. The photocatalytic formulation according to claim 1, characterized in that the other compound is the reagent or a compound that is chemically linked with an intermediate produced before the reagent is catalytically reacted and converts the final product.
3. 3. The photocatalytic formulation according to claim 1 or 2, characterized in that the photocatalyst in the presence of exposure to applied light energy produces excitation electrons and positive orifices that produce a species of active oxygen in the presence of oxygen and water on the surface of the catalyst.
4. 4. The photocatalytic formulation according to claim 3, characterized in that the other compound is the reagent applied to the catalytic reaction based on the active oxygen species, or at least one metal oxide selected from amphoteric metal oxide, metal oxides basic and oxides of acidic metals that are chemically linked to the intermediate.
5. 5. The photocatalytic formulation according to claim 4, characterized in that the amphoteric metal oxide as the other compound is at least one metal oxide selected from Al203, ZnO, SnO and Sn02, the basic metal oxide is at least one Metal oxide selected from SrO, BaO, MgO, CaO, Rb20, Na20 and K2O and the acid metal oxide is P205.
6. 6. - The photocatalytic formulation according to any of claims 2 to 5, characterized in that the other compound is formulated to satisfy a / (a + b) of about 0.0001 to 0.8, where a represents the weight of the other compound and b represents the weight of the photocatalyst.
7. 7. The photocatalytic formulation according to any of claims 2 to 6, characterized in that the photocatalyst and the other compound are regulated in and formulated to a particle diameter range of approximately 0.005 to 0.5 μm.
8. 8. - The photocatalytic formulation according to any of claims 1 to 7, characterized in that heat comprises in addition to the photocatalyst and the other compound, a third component of a compound to which a hydroxyl group can be chemically bound, and chemically absorbed and retained from the group hydroxyl to the surface of the photocatalyst and the compound as the third component, wherein the retained hydroxyl group develops hydrophilicity.
9. 9. - The photocatalytic formulation according to claim 8, characterized in that the compound as the third component has heat of wetting equal to or greater than that of the photocatalyst.
10. 10. The photocatalytic formulation according to claim 9, characterized in that the compound as the third component is at least one metal oxide selected from Si02, Al203, Zr02, Ge02, Th02 and ZnO.
11. 11. The photocatalytic formulation according to any of claims 8 to 10, characterized in that it further comprises a fourth component of an antimicrobial metal in addition to the photocatalyst, the other compound and the compound as the third component, the metal as the fourth component is Holds in the photocatalyst.
12. 12. - The photocatalytic formulation according to claim 11, characterized in that the metal as the fourth component has a reduction potential that is not less than the potential of free electrons emitted by the photocatalyst.
13. 13. The photocatalytic formulation according to claim 12, characterized in that the metal as the fourth component is at least one member selected from silver, copper, palladium, iron, nickel, chromium, cobalt, platinum, gold, lithium, calcium, magnesium, aluminum, zinc, rhodium and ruthenium.
14. 14. The photocatalytic formulation according to claim 13, characterized in that the metal as the fourth component is formulated to satisfy c / d of approximately 0.0001 to 0.05 where c represents the weight of the selected metal as the fourth component and d represents the weight of the photocatalyst.
15. 15. A photocatalyst-containing material having a photocatalyst that functions as a catalyst upon exposure to light, the photocatalyst-containing material comprising the photocatalyst formulation according to any of claims 1 to 7, which have been mixed and dispersed in a paint, enamel or glaze.
16. 16. - A photocatalyst-containing material having a photocatalyst that functions as a catalyst upon exposure to light, the photocatalyst-containing material comprises the photocatalyst formulation according to any of claims 8 to 14, which have been mixed and dispersed in a paint , enamel or glaze.
17. 17. A photocatalytically activatable material characterized in that it comprises a substrate layer and a surface layer that is provided on the surface of the substrate layer, the photocatalytically activatable material becomes photocatalytically active upon exposure to light, the surface layer comprises the formulation photocatalyst according to any of claims 1 to 7, or comprises the photocatalyst-containing material according to claim 15.
18. 18. A photocatalytically activatable material comprising a substrate layer and a surface layer that is provided on the surface of the substrate layer, the photocatalytically activatable material becomes photocatalytically active upon exposure to light, the surface layer comprises the photocatalyst formulation according to any of claims 8 to 14, or comprises the photocatalyst-containing material in accordance with the claim 16. The photocatalytically activatable material according to claim 18, characterized in that the surface layer has a geometry that satisfies the following requirements: (1) and (2): (1) thickness of the surface layer from about 0.01 to 3.0 μm; and (2) the difference in color of the surface layer between before the ultraviolet irradiation and after the ultraviolet irradiation of the surface layer with a 1% silver nitrate solution deposited there, for 5 minutes at an ultraviolet intensity in the surface layer of 1.2 nW / cm2, E: 1 to 50. 20. A photocatalytically activatable material comprising a substrate layer and a surface layer that is provided on the surface of the substrate, the photocatalytically activatable material is photocatalytically active upon exposure In light, the surface layer is formed using the photocatalyst formulation according to any of claims 1 to 14 on the surface of the substrate layer through a binder. 21. The photocatalytically activatable material according to claim 20, characterized in that the binder is one that polymerizes or melts below the temperature at which the material quality of the substrate layer is changed, to bind the photocatalytic formulation on the surface of the substrate layer. 22. The photocatalytically activatable material according to claim 20 or 21, characterized in that the binder is an enamel or a paint. 23. A photocatalytically activatable material comprising a substrate layer and a surface layer that is provided on the surface of the substrate layer, the photocatalytically activatable material becomes photocatalytically active upon exposure to light, the surface layer comprises Ti02 as a photocatalyst that also Al203, Si02 and an antimicrobial metal. 24. - The photocatalytically activatable material according to any of claims 17 to 23, characterized in that the substrate layer comprises a substrate selected from ceramics, resins, metals, glasses, earthenware or pottery, wood, calcium silicate boards, concrete boards, cement boards, extruded cement boards, gypsum boards and lightweight concrete boards subjected to key auto. 25. The photocatalytically activatable material according to any of claims 17 to 24, characterized in that the surface layer has been heat-treated. 26. The photocatalytically activatable material according to any of claims 17 to 25, characterized in that an antimicrobial metal or metal compounds are anchored on the surface of the surface layer. 27.- A process for producing a photocatalytically activatable material comprising a substrate layer and a surface layer that is provided on the surface of the substrate layer, the photocatalytically activatable material becomes photocatalytically active upon exposure to light, the process is characterized in that it comprises the steps of: providing the photocatalytic formulation according to any one of claims 1 to 14, or a photocatalytic formulation dispersed in sol, with the photocatalytic formulation dispersed therein.; layering the photocatalytic formulation or photocatalytic formulation dispersed in sol from the surface of the substrate layer (layering step); and form the surface layer. 28.- The method according to claim 27, characterized in that the stage of forming layers involves the step of placing, coating or printing the photocatalytic formulation or the photocatalytic formulation dispersed in sol on the surface of the substrate layer to form a layer of the photocatalytic formulation or the photocatalytic formulation dispersed in sol. 29. A process for producing a photocatalytically activatable material comprising a substrate layer and a surface layer that is provided on the surface of the substrate layer, the photocatalytically activatable material is photocatalytically active upon exposure to light, the process is characterized in that it comprises the steps of: providing the photocatalytic formulation according to any of claims 1 to 14, or the photocatalytic formulation dispersed in sol with the photocatalytic formulation dispersed therein; layered a binder on the surface of the substrate layer to form a binder layer; layering the photocatalytic formulation or the photocatalytic formulation dispersed in sol on the surface of the binder layer; and heat treating the structure according to the properties of the binder to form a surface layer. 30. The process according to claim 29, characterized in that the binder is an enamel or glaze and in forming the surface layer, the heat treatment is carried out at a temperature of 30 to 360 ° C above the softening temperature of the glazing and below at a temperature at which the quality of the substrate constituting the substrate layer is changed. 31. The process according to claim 29, characterized in that the binder is a paint and in forming the surface layer, the heat treatment is carried out below a temperature at which the quality of the substrate constituting the substrate layer is change 32. - The method according to claim 30, characterized in that in forming the surface layer the heat treatment is carried out at a temperature of about 150 to 1,300 ° C. 33. The method according to any of claims 27 to 32, characterized in that it further comprises, subsequent to the step of forming the surface layer, the step of coating a solution containing an antimicrobial metal or a metal compound dispersed there, and the surface of the surface layer and the step of anchoring the metal or a metal oxide on the surface of the surface layer. 34. - The method according to any of claims 27 to 32, characterized in that the step of layering comprises layering the photocatalytic formulation or the photocatalytic formulation dispersed in sol and then coating a solution containing an antimicrobial metal or compound metal therein dispersed, and the step of forming the surface layer, simultaneously comprises with the formulation of the surface layer, anchoring the metal or metal oxide on the surface of the surface layer. The method according to any of claims 27 to 32, characterized in that it also comprises, subsequent to the step of forming the surface layer, the step of coating an aqueous metal salt solution containing antimicrobial metal ions on the surface of the surface layer and the step of irradiating the surface layer with ultraviolet light to reduce the metal ions in the photocatalyst, thereby supporting and fixing the metal in the photocatalyst in the surface layer. 36.- A process for producing the photocatalyst formulation according to claim 11, comprising the photocatalyst that functions as a catalyst upon exposure to light, the other compound, the compound as the third component and the metal as the fourth component, process is characterized in that it comprises the steps of: providing a photocatalyst dispersed in sol containing there dispersed at least the photocatalyst between the photocatalyst, the other compound, and the compounds as the third compound; and mixing the photocatalyst dispersed in sol with an aqueous solution of metal salt containing antimicrobial metal ions and supporting the metal as the fourth component in the photocatalyst. 36.- A process for producing the photocatalyst formulation according to claim 11, comprising the photocatalyst that functions as a catalyst upon exposure to light, the other compound, the compound as the third component and the metal as the fourth component, process is characterized in that it comprises the steps of: providing a photocatalyst dispersed in sol containing therein dispersed at least the photocatalyst between the photocatalyst, the other compound, and the compounds as the third compound; and mixing the photocatalyst dispersed in sol with an aqueous solution of metal salt containing antimicrobial metal ions, co-precipitating the metal salt and the photocatalyst and supporting the metal as the fourth component in the photocatalyst. 38.- A process for producing the photocatalytic formulation according to claim 11, characterized in that it comprises the photocatalyst that functions as a catalyst upon exposure to light, the other compound, the compound as the third component and the metal as the fourth component, the process is characterized in that it comprises the steps of: providing a photocatalyst dispersed in sol containing therein dispersed at least the photocatalyst between the photocatalyst, the other compound, and the compounds as the third compound; and mixing the photocatalyst dispersed in sol with an aqueous solution of metal salt containing antimicrobial metal ions, irradiating the mixture with ultraviolet light to photoreduce the metal ions, thereby supporting the metal as the fourth component in the photocatalyst.