Mesoporous silica and method for producing same

Abstract

The present invention provides a method for producing mesoporous silica by an extraction method that does not involve the use of an alcohol (organic solvent), which is a hazardous substance. The present invention is a method for producing mesoporous silica, the method including a step (A) for mixing a templating agent and a silica raw material to form a mesoporous silica precursor and a step (B) for extracting the templating agent from the mesoporous silica precursor using an aqueous solution containing a template extraction agent, the method for producing mesoporous silica being characterized in that the templating agent contains a cationic surfactant and the template extraction agent contains an anionic surfactant, or the templating agent contains an anionic surfactant and the template extraction agent contains a cationic surfactant.

Description

Mesoporous silica and method for producing the same

[0001] This invention relates to mesoporous silica and a method for producing the same.

[0002] Methods for producing mesoporous silica include calcination and extraction. Calcination has advantages such as completely removing organic matter like mold agents and forming a strong silica skeleton, but it also has disadvantages such as partial pore collapse, a significant decrease in silanol groups, particle aggregation, inability to retain organic functional groups, and a long time to produce mesoporous silica. On the other hand, extraction has advantages such as retaining silanol groups and organic functional groups and preventing silica shrinkage, but it has disadvantages such as difficulty in removing organic matter and the need to use organic solvents. For example, Japanese Patent Publication No. 2004-250265 describes a method for producing mesoporous silica characterized by mixing an alkaline silicate solution with a cationic surfactant, heating it, filtering, washing with water, and drying to obtain a mesoporous silica precursor, and then extracting and removing the surfactant from the obtained mesoporous silica precursor using an organic acid-containing solvent with a water content of at least 40% by mass. However, this method requires the use of alcohol (an organic solvent), which is a hazardous material. Furthermore, Japanese Patent Publication No. 2021-159869 describes an adsorbent containing mesoporous silica in which metal atoms have been introduced into the siloxane bonds of the silica pore walls, characterized in that the mesoporous silica adsorbs basic compounds in solution. However, in order to expand the application fields of the mesoporous silica, improvements in dispersion stability in solution, coexistence stability with solutes, and adhesion to binder resins used in coatings and films are required. If silanol groups can be retained in the mesoporous silica in which metal atoms have been introduced into the siloxane bonds of the silica pore walls, it is expected that the application fields of the mesoporous silica will expand. However, the extraction method described in Japanese Patent Publication No. 2004-250265 uses organic acids, making it difficult to dope the mesoporous silica with metal.

[0003] Japanese Patent Publication No. 2004-250265 Japanese Patent Publication No. 2021-159869

[0004] The present invention aims to provide a method for producing mesoporous silica by an extraction method that does not use (or reduces the amount of alcohol used) which is a hazardous substance, in the process of extracting the template material. Furthermore, it aims to provide mesoporous silica having a hexagonal structure, which is a highly regular pore structure, and is metal-doped with silanol groups.

[0005] The present invention is configured as follows: (1) A method for producing mesoporous silica, comprising the steps of: (A) mixing a template agent and a silica raw material to form a mesoporous silica precursor; and (B) extracting the template agent from the mesoporous silica precursor using an aqueous solution containing a template extractant, wherein the template agent contains a cationic surfactant and the template extractant contains an anionic surfactant, or the template agent contains an anionic surfactant and the template extractant contains a cationic surfactant. (2) The method according to (1), wherein step (A) comprises mixing the template agent and the silica raw material with at least one compound selected from the group consisting of water-soluble aluminum compounds, water-soluble iron compounds, aluminum alkoxides, and iron alkoxides. [3] The manufacturing method according to [1] or [2], wherein step (A) comprises mixing at least one compound selected from the group consisting of a water-soluble copper compound, a water-soluble zinc compound, a copper alkoxide, and a zinc alkoxide with a template and a silica raw material. [4] 4 silanol groups per unit surface area / nm 2 [5] A mesoporous silica having a hexagonal structure and being doped with a metal. [6] The mesoporous silica according to [4], wherein the metal is copper and is doped with 0.3% by mass or more of copper. [7] The mesoporous silica according to [4] or [5], further having an organic functional group that exhibits acetaldehyde deodorizing performance. [8] The mesoporous silica according to [4] or [5], wherein the alkali metal content is 1.0% by mass or less.

[0006] According to the present invention, since alcohol (an organic solvent), which is a hazardous substance, is not used (or its usage can be reduced) in the process of extracting the mold agent, a method for producing mesoporous silica that is not limited to a specific location can be provided. Furthermore, the present invention provides mesoporous silica that has good water dispersibility due to having a large amount of silanol groups and exhibits high deodorizing performance due to having a hexagonal structure, which is a highly regular pore structure doped with metal.

[0007] This is the FT-IR spectrum of the mesoporous silica of Example 7, measured by transmission. This is the XRD spectrum of the mesoporous silica of Example 2.

[0008] The present invention provides a method for producing mesoporous silica, comprising the steps of (A) mixing a template agent and a silica raw material to form a mesoporous silica precursor, and (B) extracting the template agent from the mesoporous silica precursor using an aqueous solution containing a template extractant.

[0009] The method for mixing the template agent and the silica raw material is not particularly limited. For example, the template agent and the silica raw material may be added to the solvent simultaneously or sequentially. In order to obtain mesoporous silica having a uniform pore size and a high specific surface area, the template agent is added to the solvent and stirred, preferably at a temperature of 20°C to 200°C and for 30 minutes to 10 hours, to form micelles. Then the silica raw material is added and mixed to accumulate the silica raw material on the surface of the micelles.

[0010] Examples of solvents include water, ethanol, and toluene. The solvent is preferably water only, but may also be water containing organic solvents such as ethanol, toluene, diethyl ether, and alkylene glycol. The water containing the organic solvent preferably has a water content of 50% by mass or more, and more preferably 90% by mass or more.

[0011] As a template agent, a cationic surfactant or anionic surfactant can be used as the main component, and it is preferable that it consists only of a cationic surfactant or anionic surfactant, from the viewpoint of neutralizing the charge of the template agent by the template extractant in the process of extracting the template agent. The template agent may contain a cationic surfactant as the main component and a nonionic surfactant, an amphoteric surfactant, and / or anionic surfactant as a secondary component. Alternatively, the template agent may contain an anionic surfactant as the main component and a nonionic surfactant, an amphoteric surfactant, and / or cationic surfactant as a secondary component. When the template agent contains secondary components, the molar ratio of the main component to the secondary component is preferably 75:25 to 99.9:0.1 in order to obtain a hexagonal structure which is a highly regular pore structure. In this specification, the main component means the component that accounts for more than 50 mol% of the constituent components of the subject. For example, if the main component of the template agent is a cationic surfactant, the template agent contains more than 50 mol% of the cationic surfactant, and the remainder is a nonionic surfactant, an amphoteric surfactant, and / or anionic surfactant.

[0012] When a cationic surfactant is used as the main component of the template, the amount of template added is preferably 50 to 400 mmol / L, more preferably 50 to 150 mmol / L. Furthermore, since the template functions as a molecular template for electrostatically accumulating silica raw materials on the surface of the formed micelles, it is preferable to add 0.01 to 5 moles of template material per mole of silica raw material, and more preferably 0.05 to 1 mole. Note that if the template contains a cationic surfactant as the main component and a nonionic surfactant, amphoteric surfactant, and / or anionic surfactant as minor components, the amount of template material added is the sum of these. When a cationic surfactant is used as the main component of the template, the amount of silica raw material added is preferably 0.2 to 1.8 mol / L, more preferably 0.2 to 0.9 mol / L. When the solvent contains water, it is preferable to add 0.001 to 0.05 moles of silica raw material per mole of water.

[0013] When an anionic surfactant is used as the main component of the templating agent, the addition amount of the templating agent is preferably 10 to 80 mmol / L, more preferably 10 to 30 mmol / L. Further, since the templating agent functions as a molecular template that electrostatically accumulates the silica raw material on the surface of formed micelles, it is preferable to add 0.01 to 5 moles of the templating agent relative to 1 mole of the silica raw material, and more preferably 0.05 to 1 mole. Note that when the templating agent contains an anionic surfactant as the main component and a nonionic surfactant, an amphoteric surfactant and / or a cationic surfactant as auxiliary components, the addition amount of the templating agent is the total value of these components. When an anionic surfactant is used as the main component of the templating agent, the addition amount of the silica raw material is preferably 0.2 to 1.8 mol / L, more preferably 0.2 to 0.9 mol / L. When the solvent contains water, it is preferable to add 0.001 to 0.05 moles of the silica raw material relative to 1 mole of water.

[0014] After mixing the templating agent and the silica raw material, the silica raw material is subjected to hydrolysis and dehydration condensation to form a mesoporous silica precursor. The hydrolysis and dehydration condensation of the silica raw material are carried out, for example, by adding a basic aqueous solution or an acidic aqueous solution as a catalyst, increasing or decreasing the pH of the solution, and stirring under constant pH conditions to promote self-assembly. Stirring is performed for, for example, 1 hour or more and 72 hours or less. Through the addition of the basic aqueous solution or acidic aqueous solution, the silica raw material accumulated on the surface of the micelles undergoes dehydration condensation to form silica walls. The mesoporous silica precursor obtained in this way preferably has a hexagonal structure.

[0015] Examples of the basic aqueous solution include aqueous solutions of sodium hydroxide, sodium carbonate, ammonia and the like. The basic aqueous solution is preferably a sodium hydroxide aqueous solution. Any one of these basic aqueous solutions may be used alone, or two or more thereof may be used in combination. The basic aqueous solution is preferably added to the solvent containing the templating agent and the silica raw material such that the pH immediately after addition is 6 to 14. When the templating agent contains a cationic surfactant as the main component, stirring after adding the basic aqueous solution is preferably performed at a pH of 6 to 11, and when the templating agent contains an anionic surfactant as the main component, stirring is preferably performed at a pH of 8 to 10.

[0016] Examples of acidic aqueous solutions include aqueous solutions of hydrochloric acid, acetic acid, and nitric acid. The acidic aqueous solution is preferably an aqueous solution of an inorganic acid, and more preferably an aqueous solution of hydrochloric acid. These acidic aqueous solutions may be used individually or in combination of two or more. The acidic aqueous solution is preferably added to the solvent containing the template agent and silica raw material so that the pH immediately after addition is 1 to 4. When the template agent contains a cationic surfactant as its main component, stirring is preferably performed at a pH of 1 to 2, and when the template agent contains an anionic surfactant as its main component, stirring is preferably performed at a pH of 1 to 2.

[0017] The method for extracting a template agent from a mesoporous silica precursor using an aqueous solution containing a template extractant is not particularly limited. For example, since a mesoporous silica precursor formed by condensing silica raw materials precipitates, the mesoporous silica precursor can be recovered by, for example, filtration of this precipitate. Filtration can be performed, for example, by suction filtration, and the filtrate can be repeatedly washed with water until the pH of the filtrate is 4 to 9, preferably 5 to 8. The template agent may be extracted from the mesoporous silica precursor cake (mesoporous silica precursor containing 25 to 95 parts by mass of water) recovered in this way. Alternatively, the mesoporous silica precursor recovered in this way may be dried into a powder (mesoporous silica precursor containing less than 25 parts by mass of water) before the template agent is extracted. In the prior art described in Patent Document 1 above, it was necessary to thoroughly dry the mesoporous silica precursor before extracting the template agent in order to increase the extraction rate of the template agent. While the drying process is preferable from the viewpoint of promoting crosslinking of the mesoporous silica precursor and obtaining mesoporous silica with a uniform pore structure, if the water mass is reduced to less than 25 parts by mass, the particles may aggregate into hard clumps during the drying process. In such cases, a separate redispersion process, such as dry grinding, is necessary before the extraction process. In the present invention, since the extraction process for the template agent from the mesoporous silica precursor is carried out in water, even a mesoporous silica precursor in a hydrated state can be well redispersed in the extraction solution, and the extraction process can be carried out without special equipment for redispersion. Furthermore, by performing the extraction process using a mesoporous silica precursor in a hydrated state, the specific surface area of ​​the mesoporous silica from which the template agent has been extracted increases, improving its deodorizing properties against odor components. The water content of the mesoporous silica precursor that is brought into contact with the aqueous solution containing the template extractant is preferably 5 to 95 parts by mass, more preferably 10 to 90 parts by mass, even more preferably 25 to 90 parts by mass, and most preferably 65 to 88 parts by mass, per 100 parts by mass of the total mass of the mesoporous silica precursor in its hydrated state.

[0018] Extraction of a template from a mesoporous silica precursor can be performed, for example, by adding and dissolving a template-extracting agent in water, dispersing the mesoporous silica precursor in this solution, and stirring preferably under conditions of 5°C to 100°C for 5 minutes to 72 hours, more preferably under conditions of 15°C to 60°C for 1 hour to 30 hours. Repeated extraction of the template can improve the extraction rate of the template. According to the production method of the present invention, mesoporous silica can be obtained while maintaining the structure of the mesoporous silica precursor. In the present invention, it is preferable to produce mesoporous silica having a hexagonal structure by extracting the template from a mesoporous silica precursor having a hexagonal structure using a template-extracting agent. As the solvent used for extracting the template, it is preferable to use only water, but water that unavoidably contains an organic solvent such as alcohol derived from a raw material or alkylene glycol may also be used. The water that unavoidably contains the organic solvent preferably has a water content of 95% by mass or more, and more preferably 99% by mass or more. The aqueous solution containing the template-extracting agent may be an acidic aqueous solution containing an acidic compound, or may be an alkaline aqueous solution containing an alkaline compound. It is preferable that the aqueous solution containing the template-extracting agent does not contain hydrogen peroxide or the other substances that decompose organic matter. The mesoporous silica obtained after extracting the template may be washed with water and dried as necessary. Washing is performed, for example, by redispersion in water and suction filtration, followed by repeated washing with water until the pH of the filtrate reaches 4 to 9, preferably 5 to 7. For the purpose of improving washing efficiency, water added with an acid can also be used. From the perspective of maintaining a high amount of silanol groups in the mesoporous silica, drying after washing is preferably performed at 40°C to 150°C for 5 minutes to 24 hours.

[0019] The template agent is not only physically trapped within the silica pores, but is also strongly bound to the silica electrostatically due to having a different charge. Releasing this electrostatic bond between the template agent and silica is key to improving the extraction rate. The template extractant uses a surfactant with the opposite charge to the surfactant that is the main component of the template agent as its main component. That is, if the template agent contains a cationic surfactant as its main component, the template extractant contains an anionic surfactant as its main component, and if the template agent contains an anionic surfactant as its main component, the template extractant contains a cationic surfactant as its main component. It is preferable that the template extractant consists only of an anionic surfactant or a cationic surfactant from the viewpoint of neutralizing the charge of the template agent by the template extractant. The template extractant may contain an anionic surfactant as its main component and nonionic surfactants, amphoteric surfactants and / or cationic surfactants as minor components. Alternatively, the template extractant may contain a cationic surfactant as its main component and nonionic surfactants, amphoteric surfactants and / or anionic surfactants as minor components. When the template extractant contains minor components, the molar ratio of the main component to the minor components is preferably 75:25 to 99.9:0.1.

[0020] When an anionic surfactant is used as the main component of the template extractant, the amount of template extractant added is preferably 10 to 1000 mmol / L, more preferably 10 to 500 mmol / L. Furthermore, in order to sufficiently remove the template agent from the mesoporous silica precursor, it is preferable to add 2.5 to 100 moles of template extractant per mole of template agent, more preferably 3 to 30 moles. If the amount of template extractant per mole of template agent is 30 moles or less, the viscosity of the extraction solution is low and extraction by diffusion of substances can be performed efficiently. Note that if the template extractant contains an anionic surfactant as the main component and nonionic surfactants, amphoteric surfactants and / or cationic surfactants as minor components, the amount of template extractant added is the sum of these values.

[0021] When a cationic surfactant is used as the main component of the template extractant, the amount of template extractant added is preferably 10 to 1000 mmol / L, more preferably 10 to 500 mmol / L. Furthermore, in order to sufficiently remove the template agent from the mesoporous silica precursor, it is preferable to add 2.5 to 100 moles of template extractant per mole of template agent, more preferably 3 to 30 moles. If the amount of template extractant per mole of template agent is 30 moles or less, the viscosity of the extraction solution is low and extraction by diffusion of substances can be performed efficiently. Note that if the template extractant contains a cationic surfactant as the main component and a nonionic surfactant, amphoteric surfactant and / or anionic surfactant as minor components, the amount of template extractant added is the sum of these values.

[0022] The cationic surfactant used as a template agent or template extractant is not particularly limited. The cationic surfactant is preferably an alkylammonium salt. The alkylammonium salt is preferably one having an alkyl group with 8 to 22 carbon atoms in the main chain, and more preferably one having an alkyl group with 12 to 18 carbon atoms in the main chain, considering the ease of industrial availability, and even more preferably alkylammonium halides such as alkylammonium chloride and alkylammonium bromide. Examples of alkylammonium salts include hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, stearyltrimethylammonium bromide, stearyltrimethylammonium chloride, dodecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, didodecyldimethylammonium bromide, ditetradecyldimethylammonium bromide, didodecyldimethylammonium chloride, and ditetradecyldimethylammonium chloride. These surfactants may be used individually or in combination of two or more. In particular, as a template agent, it is preferable to use an alkylammonium salt with 12 to 18 carbon atoms in the main chain, from the viewpoint of contributing to micelle formation ability and uniform accumulation of silica raw materials, obtaining mesoporous silica with appropriate pore size and uniform pore structure, and expecting improvements in the specific surface area and pore volume of the mesoporous silica. As a template extractant, from the viewpoint of efficiency in template removal and maintenance of the silica structure, it is preferable to use one having an alkyl group with the same or fewer carbon atoms in the main chain as the template agent.

[0023] The anionic surfactant used as a template or template extractant can be any compound having an anionic functional group such as a carboxyl group, a sulfo group, or a sulfate ester group, and having 8 to 24 carbon atoms in its main chain (excluding the carbon atoms of the carboxyl group). The main chain may be linear or branched. Examples include fatty acid salts, alkyl sulfate ester salts, alkyl sulfonates, and alkyl phosphate ester salts, with alkyl sulfate ester salts being preferred. Examples of alkyl sulfate salts include sulfate salts of higher alcohols, sulfate salts of fatty acids, alkyl ether sulfate salts, alkylphenyl ether sulfate salts, glyceride sulfate salts, polyoxyalkylene alkyl ether sulfate salts, polyoxyalkylene alkylphenyl ether sulfate salts, sulfate salts of fatty acid alkanolamides or their alkylene oxide adducts, and alkali metal salts of alkyl sulfate esters such as sodium dodecyl sulfate, potassium dodecyl sulfate, sodium laureth sulfate, potassium laureth sulfate, and sodium 2-ethylhexyl sulfate; ammonium salts of alkyl sulfate esters such as ammonium dodecyl sulfate and ammonium laureth sulfate; and ethanolamine salts of alkyl sulfate esters such as monoethanolamine dodecyl sulfate, diethanolamine dodecyl sulfate, triethanolamine dodecyl sulfate, monoethanolamine laureth sulfate, diethanolamine laureth sulfate, and triethanolamine laureth sulfate. Among these, sodium salts of alkyl sulfates, ammonium salts of alkyl sulfates, and ethanolamine salts of alkyl sulfates are preferred, with ammonium salts of alkyl sulfates being particularly preferred, as they can increase the specific surface area of ​​mesoporous silica. These surfactants may be used individually or in combination of two or more. In particular, as a template agent, sodium salts of alkyl sulfates, ammonium salts of alkyl sulfates, and ethanolamine salts of alkyl sulfates are preferred from the viewpoint of having high affinity with silica raw materials and exhibiting stable surfactant activity during the formation of the silica skeleton.As a template extractant, it is preferable to use one that has an alkyl group with the same or fewer carbon atoms in its main chain as the template, from the viewpoint of efficiency in template removal and maintenance of the silica structure.

[0024] The nonionic surfactant used as a template agent and template extractant is not particularly limited. Examples include polyethylene glycol-type nonionic surfactants such as polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid glycerol ester, polyoxyethylene glycerol fatty acid, and polyoxyethylene-polyoxypropylene-block polymer; polyhydric alcohol-type nonionic surfactants such as sorbitan fatty acid ester; and amide-type nonionic surfactants such as fatty acid alkylolamide.

[0025] The amphoteric surfactants used as template agents and template extractants are not particularly limited. Examples include alkylaminopropionates, alkyldimethylbetaine, imidazoline-type amphoteric surfactants, amine oxide-type amphoteric surfactants, and glycine-type amphoteric surfactants.

[0026] When a cationic surfactant is used as the main component of the template, from the viewpoint of extraction efficiency, preferred combinations of the template and template extractant are alkylammonium salts having an alkyl group with 12 to 18 carbon atoms in the main chain and ammonium salts of alkyl sulfate esters having 8 to 24 carbon atoms in the main chain, and alkylammonium salts having an alkyl group with 12 to 18 carbon atoms in the main chain and ethanolamine salts of alkyl sulfate esters having 8 to 24 carbon atoms in the main chain. More preferred combinations are alkylammonium halides having an alkyl group with 12 to 18 carbon atoms in the main chain and ammonium salts of alkyl sulfate esters having 8 to 24 carbon atoms in the main chain, and alkylammonium halides having an alkyl group with 12 to 18 carbon atoms in the main chain and ethanolamine salts of alkyl sulfate esters having 8 to 24 carbon atoms in the main chain. Even more preferred combinations are hexadecyltrimethylammonium halide and ammonium dodecyl sulfate, hexadecyltrimethylammonium halide and ammonium laureth sulfate, and hexadecyltrimethylammonium halide and triethanolamine dodecyl sulfate.When an anionic surfactant is used as the main component of the template, preferred combinations of the template and template extractant are an ammonium salt of an alkyl sulfate ester having 8 to 24 carbon atoms in the main chain and an alkylammonium salt having an alkyl group having 12 to 18 carbon atoms in the main chain, or an ethanolamine salt of an alkyl sulfate ester having 8 to 24 carbon atoms in the main chain and an alkylammonium salt having an alkyl group having 12 to 18 carbon atoms in the main chain. A more preferred combination is a sodium salt of an alkyl sulfate ester having 8 to 24 carbon atoms in the main chain and an alkyl group having 12 to 18 carbon atoms in the main chain. These include alkylammonium halides, alkylammonium halides having an ammonium salt of an alkyl sulfate ester with 8 to 24 carbon atoms in the main chain and an alkyl group having 12 to 18 carbon atoms in the main chain, and alkylammonium halides having an ethanolamine salt of an alkyl sulfate ester with 8 to 24 carbon atoms in the main chain and an alkyl group having 12 to 18 carbon atoms in the main chain. More preferably, these combinations include ammonium dodecyl sulfate and dodecyltrimethylammonium halide, and ammonium laureth sulfate and dodecyltrimethylammonium halide.

[0027] The silica raw material is not particularly limited as long as it can form siloxane bonds by hydrolysis and dehydration condensation. Examples include tetraalkoxysilanes such as tetraethoxysilane, tetramethoxysilane, and tetra-n-butoxysilane, as well as sodium silicate and silane coupling agents. These silica raw materials may be used individually or in combination of two or more, regardless of the type of template. From the viewpoint of shortening the time required for dehydration condensation, it is preferable to use tetraalkoxysilane. It is preferable to use the silane coupling agent in combination with tetraalkoxysilane. The molar ratio of the silane coupling agent to the tetraalkoxysilane is preferably 0.1:99.9 to 50:50 when the template mainly contains a cationic surfactant, and 0.1:99.9 to 50:50 when the template mainly contains an anionic surfactant. Examples of silane coupling agents used in the present invention include compounds having various organic functional groups, such as amino groups (also referred to herein as alkylamino groups), epoxy groups, vinyl groups, methacrylic groups, isocyanate groups, mercapto groups, and urea groups (also referred to herein as alkylurea groups). These silane coupling agents enhance the chemical bonding between mesoporous silica and materials used in combination with it or the substrate surface to which mesoporous silica is attached, contributing to improved physical properties such as adhesion, dispersibility, durability, and crosslinking, and are appropriately selected according to the application. In the manufacturing process of mesoporous silica, by using a silane coupling agent having organic functional groups such as amino groups or urea groups as a silica raw material, it is possible to obtain mesoporous silica having a larger amount of silanol groups and organic functional groups than by reacting a silane coupling agent with mesoporous silica obtained by removing the mold agent by calcination to impart organic functional groups. In addition, the organic functional groups can be firmly fixed to the silica skeleton, and a high proportion of silanol groups, which contribute to deodorization, can be maintained. Here, the silanol group that contributes to deodorization refers specifically to the Q2 and Q3 structures in the 29Si-solid-state NMR spectrum. Examples of silane coupling agents include compounds having organic functional groups such as alkylamino groups and alkylurea groups that exhibit acetaldehyde deodorizing performance.In particular, amino group-containing silane coupling agents exhibit high reactivity with inorganic substrates and are effective in improving adhesion and dispersibility. Furthermore, by using amino group-containing silane coupling agents, it is possible to impart deodorizing properties against aldehydes in air and liquid to mesoporous silica. Representative compounds include alkylamino group-containing compounds such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-aminoethyl-3-aminopropyltrimethoxysilane, N-aminoethyl-3-aminopropyltriethoxysilane, bis(3-trimethoxysilylpropyl)amine, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, and p-aminophenyltrimethoxysilane. These compounds possess either primary or secondary amino groups and are selected according to their properties such as hydrolysis resistance, reactivity, crosslinking ability, and heat resistance. Examples of silane coupling agents containing functional groups other than amino groups include the following compounds. Examples of epoxy group-containing silane coupling agents include γ-glycidyloxypropyltrimethoxysilane and γ-glycidyloxypropyltriethoxysilane. Examples of vinyl group-containing silane coupling agents include vinyltrimethoxysilane and vinyltriethoxysilane. Examples of methacrylic group-containing silane coupling agents include γ-methacryloxypropyltrimethoxysilane and γ-methacryloxypropyltriethoxysilane. Examples of isocyanate group-containing silane coupling agents include 3-isocyanatetopropyltrimethoxysilane. Examples of mercapto group-containing silane coupling agents include 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane. Examples of urea group-containing silane coupling agents include 1-[3-(trimethoxysilyl)propyl]urea. In particular, by using urea group-containing silane coupling agents, mesoporous silica can be given the function of selective metal extraction from liquid media.Furthermore, silane coupling agents having functional groups such as alkyl groups, phenyl groups, chloro groups, acrylic groups, carboxyl groups, hydroxyl groups, polyol groups, fluoroalkyl groups, sulfo groups, and thiourea groups can also be used. Specific examples include methyltrimethoxysilane, phenyltrimethoxysilane, chloromethyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, 3-carboxypropyltrimethoxysilane, 3-hydroxypropyltrimethoxysilane, polyethylene glycol monomethyl ether silane, trifluoropropyltrimethoxysilane, sulfopropyltrimethoxysilane, and 3-thioureidopropyltrimethoxysilane. These silane coupling agents may be used individually, or multiple types may be used in combination to obtain synergistic effects. Note that the above compounds are examples, and the silane coupling agents used in the present invention are not limited to these.

[0028] In the present invention, when mixing a template agent and a silica raw material to form a mesoporous silica precursor, at least one compound selected from the group consisting of water-soluble aluminum compounds, water-soluble iron compounds, aluminum alkoxides, and iron alkoxides may be added. This dops the mesoporous silica with aluminum and / or iron, thereby suppressing the hydrolysis of the mesoporous silica. These compounds may be added before adding the silica raw material to the solvent, before dehydration condensation, simultaneously with dehydration condensation, or after dehydration condensation, but preferably before dehydration condensation of the silica raw material, and more preferably before adding the silica raw material to the solvent. In order to efficiently dope the mesoporous silica with aluminum and / or iron, it is preferable to add the template agent and the compound to the solvent, stir preferably at a temperature of 20°C to 200°C and for 30 minutes to 10 hours to form micelles, and then add and mix the silica raw material to accumulate the silica raw material on the surface of the micelles.

[0029] Examples of water-soluble aluminum compounds include aluminum chloride, aluminum sulfate, aluminum acetate, aluminum nitrate, potassium aluminum sulfate, aluminum ammonium sulfate, aluminum sodium sulfate, and their hydrates. Examples of water-soluble iron compounds include ferrous chloride, ferrous nitrate, ferrous sulfate, ferrous acetate, ferric chloride, ferric nitrate, ferric sulfate, ferric acetate, and their hydrates. Examples of aluminum alkoxides include aluminum compounds having ethoxy, isopropoxy, or butoxy groups, as well as aluminum acetylacetonate. Examples of iron alkoxides include iron compounds having ethoxy, isopropoxy, or butoxy groups, as well as iron acetylacetonate.

[0030] The amount of water-soluble aluminum compounds and aluminum alkoxides added to the solvent should be such that, for example, the amount of aluminum is 0.001 to 0.3 moles per mole of silicon in the silica raw material. The amount of water-soluble iron compounds and iron alkoxides added to the solvent should be such that, for example, the amount of iron is 0.001 to 0.5 moles per mole of silicon in the silica raw material. When using a compound containing aluminum and a compound containing iron in combination, the total amount of aluminum and iron should be such that it is 0.001 to 0.3 moles per mole of silicon in the silica raw material.

[0031] Furthermore, when mixing the template agent and the silica raw material to form a mesoporous silica precursor, at least one compound selected from the group consisting of water-soluble copper compounds, water-soluble zinc compounds, copper alkoxides, and zinc alkoxides may be added. This dops the mesoporous silica with copper and / or zinc, imparting to the mesoporous silica the function of adsorbing odor components such as sulfur-containing compounds. These compounds may be added before the addition of the silica raw material to the solvent, before dehydration condensation, simultaneously with dehydration condensation, or after dehydration condensation, but preferably before the dehydration condensation of the silica raw material, and more preferably before the addition of the silica raw material to the solvent. To efficiently dope mesoporous silica with copper and / or zinc, it is preferable to add a template agent, the aforementioned compound, and at least one compound selected from the group consisting of water-soluble aluminum compounds, water-soluble iron compounds, aluminum alkoxides, and iron alkoxides to a solvent, and to stir under conditions of preferably 20°C to 200°C and 30 minutes to 10 hours to form micelles, and then add and mix the silica raw material to accumulate the silica raw material on the surface of the micelles.

[0032] Examples of water-soluble copper compounds include copper chloride, copper sulfate, copper nitrate, copper acetate, copper gluconate, copper methanesulfonate, copper sulfamate, copper fluoroborate, and their hydrates. Examples of water-soluble zinc compounds include zinc chloride, zinc sulfate, zinc nitrate, zinc acetate, zinc lactate, zinc gluconate, and their hydrates. Examples of copper alkoxides include copper compounds having ethoxy, isopropoxy, or butoxy groups, as well as copper acetylacetonate. Examples of zinc alkoxides include zinc compounds having ethoxy, isopropoxy, or butoxy groups, as well as zinc acetylacetonate.

[0033] The amount of water-soluble copper compounds and copper alkoxides added to the solvent should be such that, for example, the amount of copper is 0.001 to 0.3 moles per mole of silicon in the silica raw material. The amount of water-soluble zinc compounds and zinc alkoxides added to the solvent should be such that, for example, the amount of zinc is 0.001 to 0.3 moles per mole of silicon in the silica raw material. When using a compound containing copper and a compound containing zinc in combination, the total amount of copper and zinc should be such that it is 0.001 to 0.3 moles per mole of silicon in the silica raw material.

[0034] In this invention, "doping" refers to a state in which a metal element M is incorporated into the position of a Si element within the SiO4 framework of mesoporous silica. In other words, doping means having a Si-O-M-O-Si structure, and is different from structures in which a -Si-O-Si-O- network structure covers the surface of metal particles, structures in which metal particles are supported on silica gel, structures in which metal is immobilized on formed mesoporous silica via a silane coupling agent or resin, and structures in which the pore surface of formed mesoporous silica reacts with a metal raw material. By doping the mesoporous silica with metal, it is possible to suppress the elution of metal from the mesoporous silica in water, etc., and to exhibit functions such as adsorption of odor components (deodorizing performance) over a long period of time.

[0035] The method for producing mesoporous silica in the present invention preferably includes an acid washing step (C). By performing the acid washing step (C), organic compounds such as ammonium and alkali metals derived from the raw materials for production, contained in the mesoporous silica, can be efficiently reduced. This makes it possible to increase the specific surface area of ​​the mesoporous silica, which is calculated by measuring the specific surface area. The acid washing step (C) may be performed between the step of forming a mesoporous silica precursor (A) and the step of extracting a template agent from the mesoporous silica precursor (B), or after the step of extracting a template agent from the mesoporous silica precursor (B). Preferably, it is performed after the step of extracting a template agent from the mesoporous silica precursor (B). By performing steps (A), (B), and (C) in that order, it is possible to remove ammonium and alkali metals derived from the template extractant. After performing the acid washing step (C), a drying step may be performed as needed. The acid washing step (C) is preferably carried out by contacting the mesoporous silica precursor or mesoporous silica with washing water until the pH of the washing water after washing is 4.0 to 7.5, and more preferably until the pH is 5.0 to 7.0. By carrying out the acid washing step (C) until the pH of the washing water after washing is 4.0 to 7.5, organic compounds such as ammonium and alkali metals contained in the mesoporous silica can be sufficiently reduced. The acidic washing solution used in the acid washing step (C) is, for example, an aqueous solution with a pH of 2 to 5 containing hydrochloric acid, acetic acid, nitric acid, etc. The acid washing step (C) may be carried out by adding the mesoporous silica precursor or mesoporous silica to the acidic washing solution and stirring under conditions of 5 minutes to 72 hours, or by repeatedly changing the washing water. The method of contacting the mesoporous silica precursor or mesoporous silica with washing water is not particularly limited and can be immersion washing or spray washing.

[0036] The method for producing mesoporous silica in the present invention preferably includes a step (D) of reacting a mesoporous silica precursor with a silane coupling agent. The step (D) of reacting a mesoporous silica precursor with a silane coupling agent is performed between the step (A) of forming a mesoporous silica precursor and the step (B) of extracting a template from the mesoporous silica precursor. By performing the steps in the order of (A), (D), and (B), organic functional groups are imparted only to the outer surface of the mesoporous silica particles, thus allowing any desired function to be imparted only to the outer surface of the particles without impairing the deodorizing performance that arises from the pores of the mesoporous silica. In the method for producing mesoporous silica in the present invention, if the acid washing step (C) is performed between the step (A) of forming a mesoporous silica precursor and the step (B) of extracting a template from the mesoporous silica precursor, the steps may be performed in the order of (A), (C), (D), and (B), or in the order of (A), (D), (C), and (B). Examples of silane coupling agents include compounds having various functional groups such as amino groups, epoxy groups, vinyl groups, methacrylic groups, isocyanate groups, mercapto groups, and urea groups, as mentioned above. Compounds having organic functional groups such as alkylamino groups and alkylurea groups, which exhibit acetaldehyde deodorizing performance, are particularly preferred. Step (D) of reacting the mesoporous silica precursor with the silane coupling agent can be carried out by adding 0.01 to 10 parts by mass of the silane coupling agent to 100 parts by mass of the mesoporous silica precursor and reacting them.

[0037] The mesoporous silica of the present invention has 4 silanol groups per unit surface area / nm 2The present invention possesses the above characteristics. As a result, the mesoporous silica of the present invention has good water dispersibility. Furthermore, because the mesoporous silica of the present invention is metal-doped, for example, the silanol groups electrostatically adsorb viruses and bacteria, and then decompose them with the nearby doped metal, thereby efficiently exhibiting antiviral activity. In addition, the silanol groups instantly electrostatically adsorb odor substances, and then, over time, transfer them to the nearby doped metal, converting this to adsorption by chemical bonding, thereby preventing the re-release of odors. Moreover, the mesoporous silica of the present invention has a hexagonal structure, which is a highly regular pore structure. Due to the regularity of the pores, the pores have high durability, and long-term storage stability can be achieved even in water or high-humidity environments.

[0038] The present invention provides a method for producing mesoporous silica, from which a mesoporous silica precursor formed by mixing a template, a silica raw material, and a water-soluble metal compound and / or metal alkoxide is obtained, with a density of 4 silanol groups per unit surface area / nm. 2 The method for removing the template agent is not particularly limited, as long as it can remove the template agent while retaining the above-mentioned properties and the doped metal. The mesoporous silica of the present invention has a hexagonal structure, which is a highly regular pore structure, because it is manufactured using a template agent. Examples of methods for removing the template agent include extraction using an organic acid such as acetic acid or formic acid and alcohol, decomposition using hydrogen peroxide, and heating under relatively mild conditions of about 150°C to 300°C. However, from the viewpoint of energy efficiency and limitations of manufacturing equipment, it is preferable that the material is obtained by the manufacturing method of the present invention described above. Furthermore, according to the manufacturing method of the present invention, it is not necessary to use an organic acid that causes metal elution when extracting the template agent from the mesoporous silica precursor, so mesoporous silica with a high metal content can be obtained without adding a large amount of metal raw material during manufacturing. Moreover, according to the manufacturing method of the present invention, it is not necessary to calcine at high temperatures when removing the template agent from the mesoporous silica precursor, so the silanol groups and organic functional groups of the raw material can be efficiently retained in the mesoporous silica.

[0039] The mesoporous silica of the present invention has 4 silanol groups per unit surface area / nm2 The above properties are present. As a result, mesoporous silica has good water dispersibility. That is, powder scattering is less likely to occur when mixed with water, making it suitable for slurry production. Furthermore, aggregation in water is suppressed, and silica particles that have settled in water can be easily redispersed. In addition, it is possible to exhibit effects such as modification of mesoporous silica with silane coupling agents and improved adhesion with resin components through crosslinking reactions. The silanol groups present in mesoporous silica are 4 groups / nm per unit surface area. 2 The above is acceptable, but 4-9 particles / nm is fine. 2 It is preferable that this is the case. In this invention, the amount of silanol groups in the mesoporous silica refers to the amount of silanol groups remaining when the mesoporous silica is heated from 25°C to 350°C at a heating rate of 5°C / min.

[0040] The metal doped into the mesoporous silica of the present invention is not particularly limited. If the doped metal is aluminum and / or iron, hydrolysis of the mesoporous silica can be suppressed. If the doped metal is copper and / or zinc, excellent adsorption function for odor components such as sulfur-containing compounds can be imparted to the mesoporous silica. These metals may be used individually or in combination of two or more. In particular, combinations of aluminum and copper, or iron and copper, allow for stable dispersion of copper during doping, enabling the expression of deodorizing performance, antibacterial properties, antiviral properties, etc., over a long period of time.

[0041] The metal content in mesoporous silica is, for example, 0.01 to 40% by mass. When the metal doped into the mesoporous silica is aluminum, the aluminum content in the mesoporous silica is, for example, 0.01 to 10% by mass, preferably 0.1 to 5% by mass, and more preferably 0.5 to 3.0% by mass. If the aluminum content is 0.01% by mass or more, the hydrolysis inhibitory effect of the mesoporous silica is improved. If the aluminum content is 10% by mass or less, the specific surface area is 500 m². 2It is easy to obtain mesoporous silica with a concentration of 1 / g or more. When the metal doped into the mesoporous silica is iron, the iron content in the mesoporous silica is, for example, 0.01 to 10% by mass, preferably 0.1 to 5% by mass, and more preferably 0.5 to 3.0% by mass. If the iron content is 0.01% by mass or more, the hydrolysis inhibitory effect of the mesoporous silica is improved. If the iron content is 10% by mass or less, the specific surface area is 500 m². 2It is easy to obtain mesoporous silica with a concentration of 0.01% / g or more. When aluminum and iron are contained in the mesoporous silica, their total amount is, for example, 0.01 to 20% by mass, preferably 0.1 to 10% by mass, and more preferably 0.5 to 3.0% by mass. When the metal doped into the mesoporous silica is copper, the copper content in the mesoporous silica is, for example, 0.01 to 30% by mass, preferably 0.1 to 15% by mass, and more preferably 0.3 to 3.0% by mass. If the copper content is 0.01% by mass or more, the mesoporous silica can exhibit an excellent deodorizing effect. If the copper content is 30% by mass or less, it is easy to obtain mesoporous silica with an excellent deodorizing effect in which copper is uniformly doped into the silica skeleton. When the metal doped into the mesoporous silica is zinc, the zinc content in the mesoporous silica is, for example, 0.01 to 30% by mass, preferably 0.1 to 15% by mass, and more preferably 0.3 to 3.0% by mass. If the zinc content is 0.01% by mass or more, the mesoporous silica can exhibit excellent deodorizing effects. If the zinc content is 30% by mass or less, it is easy to obtain mesoporous silica with excellent deodorizing effects, in which zinc is uniformly doped into the silica skeleton. When copper and zinc are contained in the mesoporous silica, their total amount is, for example, 0.01 to 30% by mass, preferably 0.1 to 15% by mass, and more preferably 0.3 to 3.0% by mass. From the viewpoint of hydrolysis inhibition effect and deodorizing effect, the preferred metal content in mesoporous silica is, when aluminum and copper are contained in mesoporous silica, 0.01 to 10% by mass of aluminum and 0.01 to 30% by mass of copper; when aluminum and zinc are contained in mesoporous silica, 0.01 to 10% by mass of aluminum and 0.01 to 30% by mass of zinc; when iron and copper are contained in mesoporous silica, 0.01 to 10% by mass of iron and 0.01 to 30% by mass of copper; and when iron and zinc are contained in mesoporous silica, 0.01 to 10% by mass of iron and 0.01 to 30% by mass of zinc.A more preferable content is, when aluminum and copper are contained in mesoporous silica, 0.1 to 5% by mass of aluminum and 0.1 to 15% by mass of copper; when aluminum and zinc are contained in mesoporous silica, 0.1 to 5% by mass of aluminum and 0.1 to 15% by mass of zinc; when iron and copper are contained in mesoporous silica, 0.1 to 5% by mass of iron and 0.1 to 15% by mass of copper; and when iron and zinc are contained in mesoporous silica, 0.1 to 5% by mass of iron and 0.1 to 15% by mass of zinc. Even more preferable is, when aluminum and copper are contained in mesoporous silica, 0.5 to 3.0% by mass of aluminum and 0.3 to 3.0% by mass of copper.

[0042] The mesoporous silica of the present invention may have organic functional groups such as carboxyl groups, epoxy groups, amino groups, and urea groups in addition to silanol groups, and it is preferable that it has amino groups or urea groups. The presence of amino groups in the mesoporous silica allows it to exhibit deodorizing performance against aldehydes and acidic odors in both air and liquid. In particular, the metal-doped mesoporous silica of the present invention, by having amino groups, can deodorize aldehydes even in water. Furthermore, the presence of urea groups in the mesoporous silica can impart to the mesoporous silica a function such as selective metal extraction from liquid media. The amount of organic functional groups in the mesoporous silica can be appropriately adjusted depending on the purpose, but for example, it is preferably 0.01 to 20 mmol / g, and more preferably 0.1 to 10 mmol / g. In particular, the amount of amino groups in the mesoporous silica is preferably 0.01 to 20 mmol / g, and more preferably 0.1 to 10 mmol / g. If the amino group concentration is 0.01 mmol / g or higher, sufficient deodorizing performance against aldehydes can be achieved. If the amino group concentration is 20 mmol / g or lower, deodorizing performance against aldehydes due to the amino groups can also be achieved.

[0043] Methods for imparting organic functional groups such as amino groups or urea groups to mesoporous silica include using a silane coupling agent having organic functional groups such as amino groups or urea groups as a silica raw material in the mesoporous silica manufacturing process, or performing a step (D) in which the mesoporous silica precursor is reacted with a silane coupling agent between the step (A) of forming a mesoporous silica precursor and the step (B) of extracting a template from the mesoporous silica precursor. In the method using a silane coupling agent as a silica raw material, mesoporous silica having organic functional groups in its pores can be obtained. This method can produce mesoporous silica with a larger amount of silanol groups than the method of imparting organic functional groups by reacting a silane coupling agent with a mesoporous silica precursor obtained by dehydration condensation of a silica raw material or mesoporous silica obtained by removing the template by calcination. In addition, the organic functional groups can be firmly fixed to the silica skeleton, and a high proportion of silanol groups that contribute to deodorization can be maintained. Furthermore, by mixing a ligand that coordinates to the doped metal and a compound having an amino group with the raw materials during synthesis, it is possible to attach an amino group terminus using the doped metal as a scaffold. As the ligand, a compound containing two or more amino groups is preferred. Examples include ethylenediamine, 1,6-diaminohexane, and diethylenetriamine. In the method in which step (D) is performed between step (A) and step (B), mesoporous silica having organic functional groups only on the outer surface of the particles is obtained. Since this method allows organic functional groups to be attached only to the outer surface of the mesoporous silica particles, it is possible to attach any desired function only to the outer surface of the particles without impairing the deodorizing performance that arises from the pores of the mesoporous silica.

[0044] The mesoporous silica of the present invention has a hexagonal structure. That is, it has a regular arrangement structure in which pores partitioned by silica partition walls are arranged in a hexagonal pattern. The fact that the mesoporous silica has a hexagonal structure can be confirmed by observation with a transmission electron microscope (TEM). Also, the regularity of the pores can be confirmed by X-ray diffraction (XRD). In an XRD spectrum obtained by X-ray diffraction, when a sharp peak with high diffraction intensity appears, this indicates that the pores of the mesoporous silica are arranged at uniform intervals. In the present invention, it is preferable to have at least one peak in a diffraction angle range of 2 to 5°, and when a plurality of peaks appear, it is more preferable that the ratio of the peak positions is 1:√3:2. To obtain mesoporous silica having a regular hexagonal structure, it is preferable to produce the mesoporous silica using only one type of templating agent. When two or more types of templating agents are used, the blending ratio of the main component templating agent is preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 90 mol% or more.

[0045] The mesoporous silica of the present invention preferably has an alkali metal content of 1.0% by mass or less, more preferably 0.5% by mass or less, even more preferably 0.1% by mass or less, and it is particularly preferable that the mesoporous silica substantially contains no alkali metal. When the alkali metal content is 1.0% by mass or less, deodorizing performance is improved. The alkali metal content can be reduced by washing the mesoporous silica precursor or the mesoporous silica with an acidic aqueous solution.

[0046] The mesoporous silica of the present invention has a specific surface area of, for example, 150 m 2 / g or more, preferably 250 to 2000 m 2 / g, more preferably 700 to 1600 m 2 / g. Further, the pore diameter may be any size that allows entry and exit of solvent molecules, surfactants, and odor components, and for example, the diameter is 2 to 50 nm. Such mesoporous silica exhibits an excellent deodorizing effect against ammonia, sulfur-containing odors and the like.

[0047] [Synthesis of Mesoporous Silica Precursors] (Synthesis Example 1) Water was used as the solvent, and hexadecyltrimethylammonium chloride was added as a cationic surfactant. The mixture was stirred at room temperature for 30 minutes. Tetraethoxysilane was added as a silica raw material to the solution in which micelles had formed, and the mixture was stirred at room temperature for 1.5 hours. Next, sodium hydroxide was added as a condensation catalyst, and the mixture was stirred at room temperature for 3 hours to obtain mesoporous silica precursor 1. The amounts of each compound added per mole of tetraethoxysilane were as follows: Cationic surfactant (hexadecyltrimethylammonium chloride): 0.225 moles Water: 125 moles Sodium hydroxide: 0.325 moles

[0048] (Synthesis Example 2) To water as a solvent, hexadecyltrimethylammonium chloride as a cationic surfactant and aluminum chloride hexahydrate as a water-soluble aluminum compound (aluminum salt) were added and stirred at room temperature for 30 minutes. To the solution in which micelles had formed, tetraethoxysilane as a silica raw material was added and stirred at room temperature for 1.5 hours. Next, sodium hydroxide was added as a condensation catalyst and stirred at room temperature for 3 hours to obtain mesoporous silica precursor 2. The amounts of each compound added per mole of tetraethoxysilane were as follows: Cationic surfactant (hexadecyltrimethylammonium chloride): 0.225 moles, Aluminum chloride hexahydrate: 0.0482 moles, Water: 125 moles, Sodium hydroxide: 0.325 moles

[0049] (Synthesis Example 3) To water as the solvent, hexadecyltrimethylammonium chloride as a cationic surfactant, copper chloride dihydrate as a water-soluble copper compound (copper salt), and aluminum chloride hexahydrate as a water-soluble aluminum compound (aluminum salt) were added and stirred at room temperature for 30 minutes. To the solution in which micelles had formed, tetraethoxysilane was added as a silica raw material and stirred at room temperature for 1.5 hours. Next, sodium hydroxide was added as a condensation catalyst and stirred at room temperature for 3 hours to obtain mesoporous silica precursor 3. The amounts of each compound added per mole of tetraethoxysilane were as follows: Cationic surfactant (hexadecyltrimethylammonium chloride): 0.225 moles, copper chloride dihydrate: 0.0204 moles, aluminum chloride hexahydrate: 0.0482 moles, water: 125 moles, sodium hydroxide: 0.325 moles

[0050] (Synthesis Example 4) To water as the solvent, hexadecyltrimethylammonium chloride as a cationic surfactant, copper chloride dihydrate as a water-soluble copper compound (copper salt), and aluminum chloride hexahydrate as a water-soluble aluminum compound (aluminum salt) were added and stirred at room temperature for 30 minutes. To the solution in which micelles had formed, tetraethoxysilane was added as a silica raw material and stirred at room temperature for 1.5 hours. Next, sodium hydroxide was added as a condensation catalyst and stirred at room temperature for 3 hours to obtain mesoporous silica precursor 4. The amounts of each compound added per mole of tetraethoxysilane were as follows: Cationic surfactant (hexadecyltrimethylammonium chloride): 0.225 moles, copper chloride dihydrate: 0.0408 moles, aluminum chloride hexahydrate: 0.1205 moles, water: 125 moles, sodium hydroxide: 0.325 moles

[0051] (Synthesis Example 5) Water and ethanol were used as solvents, to which ammonium dodecyl sulfate was added as an anionic surfactant, and the mixture was stirred at room temperature for 30 minutes. To the solution in which micelles had formed, tetraethoxysilane and 3-aminopropyltriethoxysilane were added as silica raw materials, and the pH was adjusted to 10 or less using hydrochloric acid. The mixture was then stirred at room temperature for 1 hour to obtain mesoporous silica precursor 5. The amounts of each compound added per mole of tetraethoxysilane were as follows: Anionic surfactant (ammonium dodecyl sulfate): 0.200 moles, 3-aminopropyltriethoxysilane: 1 mole, Hydrochloric acid: 0.0410 moles, Water: 360 moles, Ethanol: 40 moles

[0052] (Synthesis Example 6) To water as a solvent, hexadecyltrimethylammonium chloride as a cationic surfactant and aluminum chloride hexahydrate as a water-soluble aluminum compound (aluminum salt) were added and stirred at room temperature for 30 minutes. To the solution in which micelles had formed, tetraethoxysilane as a silica raw material was added and stirred at room temperature for 1.5 hours. Next, 3-aminopropyltriethoxysilane was added and stirred for 5 minutes, then sodium hydroxide was added as a condensation catalyst and stirred at room temperature for 3 hours to obtain mesoporous silica precursor 6. The amounts of each compound added per 0.9 moles of tetraethoxysilane were as follows: Cationic surfactant (hexadecyltrimethylammonium chloride): 0.225 moles, 3-aminopropyltriethoxysilane: 0.1 mole, aluminum chloride hexahydrate: 0.0482 moles, water: 125 moles, sodium hydroxide: 0.325 moles

[0053] (Synthesis Example 7) To water as the solvent, hexadecyltrimethylammonium chloride was added as a cationic surfactant, copper chloride dihydrate as a water-soluble copper compound (copper salt), and aluminum chloride hexahydrate as a water-soluble aluminum compound (aluminum salt), and the mixture was stirred at room temperature for 30 minutes. Tetraethoxysilane was added to the solution in which micelles had formed, and the mixture was stirred at room temperature for 1.5 hours. Next, 3-aminopropyltriethoxysilane was added and stirred for 5 minutes, then sodium hydroxide was added as a condensation catalyst, and the mixture was stirred at room temperature for 3 hours to obtain mesoporous silica precursor 7. The amounts of each compound added were as follows, relative to 0.9 moles of tetraethoxysilane. • Cationic surfactant (hexadecyltrimethylammonium chloride): 0.225 moles • 3-aminopropyltriethoxysilane: 0.1 mole • Copper chloride dihydrate: 0.0204 moles • Aluminum chloride hexahydrate: 0.0482 moles • Water: 125 moles • Sodium hydroxide: 0.325 moles

[0054] (Synthesis Example 8) To water as the solvent, hexadecyltrimethylammonium chloride was added as a cationic surfactant, copper chloride dihydrate as a water-soluble copper compound (copper salt), and aluminum chloride hexahydrate as a water-soluble aluminum compound (aluminum salt), and the mixture was stirred at room temperature for 30 minutes. To the solution in which micelles had formed, tetraethoxysilane and 1-[3-(trimethoxysilyl)propyl]urea were added as silica raw materials, and the mixture was stirred at room temperature for 1.5 hours. Next, sodium hydroxide was added as a condensation catalyst, and the mixture was stirred at room temperature for 3 hours to obtain mesoporous silica precursor 8. The amounts of each compound added were as follows, relative to 0.9 moles of tetraethoxysilane. • Cationic surfactant (hexadecyltrimethylammonium chloride): 0.225 moles • 1-[3-(trimethoxysilyl)propyl]urea: 0.1 mole • Copper chloride dihydrate: 0.0204 moles • Aluminum chloride hexahydrate: 0.0482 moles • Water: 125 moles • Sodium hydroxide: 0.325 moles

[0055] [Extraction of Mold Agent] (Manufacturing Example 1) Mesoporous silica precursor 1 in solution was recovered by filtration. Water and ADS were added to 100 parts by mass of water, with 9.72 parts by mass of ammonium dodecyl sulfate (ADS) as an anionic surfactant, and 2.20 parts by mass of mesoporous silica precursor 1 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, filtered and recovered, and dried to produce mesoporous silica from which the mold agent component had been extracted and removed from the mesoporous silica precursor. The state of the mesoporous silica precursor before extraction using the anionic surfactant was a cake with a high water content.

[0056] (Manufacturing Example 2, Example 1) Mesoporous silica precursor 2 in solution was recovered by filtration and dried overnight at 100°C. The resulting mass was dry-ground using a Wonder Crusher WC-3L manufactured by Osaka Chemical Co., Ltd. to obtain a powder. Water and TEADS were added to 100 parts by mass of water to form a dispersion containing 35.10 parts by mass of dodecyl sulfate triethanolamine (TEADS) as an anionic surfactant, with 2.70 parts by mass of mesoporous silica precursor 2 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which the template component had been extracted and removed from the mesoporous silica precursor.

[0057] (Manufacturing Examples 3 and 2) Mesoporous silica precursor 2 in solution was recovered by filtration. Water and ADS were added to 100 parts by mass of water to form a dispersion containing 3.09 parts by mass of ammonium dodecyl sulfate (ADS) as an anionic surfactant, with 2.06 parts by mass of mesoporous silica precursor 2 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which the template component had been extracted and removed from the mesoporous silica precursor. The state of the mesoporous silica precursor before extraction using the anionic surfactant was a cake with a high water content.

[0058] (Manufacturing Examples 4 and 3) Mesoporous silica precursor 3 in solution was recovered by filtration and dried overnight at 100°C. The resulting mass was dry-ground using a Wonder Crusher WC-3L manufactured by Osaka Chemical Co., Ltd. to obtain a powder. Water and TEADS were added to 100 parts by mass of water to form a dispersion containing 35.10 parts by mass of dodecyl sulfate triethanolamine (TEADS) as an anionic surfactant, with 2.70 parts by mass of mesoporous silica precursor 3 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which the template component had been extracted and removed from the mesoporous silica precursor.

[0059] (Manufacturing Examples 5 and 4) Mesoporous silica precursor 3 in solution was recovered by filtration. Water and ADS were added to 100 parts by mass of water to form a dispersion containing 7.27 parts by mass of ammonium dodecyl sulfate (ADS) as an anionic surfactant, with 5.50 parts by mass of mesoporous silica precursor 3 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which the template component had been extracted and removed from the mesoporous silica precursor. The state of the mesoporous silica precursor before extraction using the anionic surfactant was a cake with a high water content.

[0060] (Manufacturing Examples 6 and 5) Mesoporous silica precursor 4 in solution was recovered by filtration. Water and ADS were added to 100 parts by mass of water to form a dispersion containing 4.66 parts by mass of ammonium dodecyl sulfate (ADS) as an anionic surfactant, with 3.43 parts by mass of mesoporous silica precursor 4 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which the template component had been extracted and removed from the mesoporous silica precursor. The state of the mesoporous silica precursor before extraction using the anionic surfactant was a cake with a high water content.

[0061] (Manufacturing Example 7) The mesoporous silica precursor 5 in solution was recovered and dried at 100°C for 2 days. The resulting mass was dry-ground using a Wonder Crusher WC-3L manufactured by Osaka Chemical Co., Ltd. to obtain a powder. A dispersion containing 2.794 parts by mass of dodecyltrimethylammonium chloride (C12TAC) as a cationic surfactant per 100 parts by mass of water, with 2.001 parts by mass of mesoporous silica precursor 5 dispersed in it, was stirred at room temperature for 2 hours. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which organic components had been extracted and removed from the mesoporous silica precursor.

[0062] (Manufacturing Examples 8 and 6) Mesoporous silica precursor 2 in solution was recovered by filtration and dried overnight at 100°C. The resulting mass was dry-ground using a Wonder Crusher WC-3L manufactured by Osaka Chemical Co., Ltd. to obtain a powder. Water and ADS were added to 100 parts by mass of water to form a dispersion containing 5.74 parts by mass of ammonium dodecyl sulfate (ADS) as an anionic surfactant, with 2.16 parts by mass of mesoporous silica precursor 2 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which the template component had been extracted and removed from the mesoporous silica precursor.

[0063] (Manufacturing Examples 9 and 7) Mesoporous silica precursor 4 in solution was recovered by filtration and dried overnight at 100°C. The resulting mass was dry-ground using a Wonder Crusher WC-3L manufactured by Osaka Chemical Co., Ltd. to obtain a powder. Water and SDS were added to 100 parts by mass of water to form a dispersion containing 5.84 parts by mass of sodium dodecyl sulfate (SDS) as an anionic surfactant, with 2.15 parts by mass of mesoporous silica precursor 4 dispersed in it. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which the template component had been extracted and removed from the mesoporous silica precursor.

[0064] (Manufacturing Examples 10 and 8) The mesoporous silica precursor 6 in solution was recovered by filtration. Water and ADS were added to 100 parts by mass of water to form a dispersion containing 3.78 parts by mass of ammonium dodecyl sulfate (ADS) as an anionic surfactant, with 2.35 parts by mass of mesoporous silica precursor 6 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which the template component had been extracted and removed from the mesoporous silica precursor. The state of the mesoporous silica precursor before extraction using the anionic surfactant was a cake with a high water content.

[0065] (Manufacturing Examples 11 and 9) The mesoporous silica precursor 7 in solution was recovered by filtration. Water and ADS were added to 100 parts by mass of water to form a dispersion containing 3.79 parts by mass of ammonium dodecyl sulfate (ADS) as an anionic surfactant, with 2.26 parts by mass of mesoporous silica precursor 7 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which the template component had been extracted and removed from the mesoporous silica precursor. The state of the mesoporous silica precursor before extraction using the anionic surfactant was a cake with a high water content.

[0066] (Manufacturing Examples 12 and 10) The mesoporous silica precursor 8 in solution was recovered by filtration. Water and ADS were added to 100 parts by mass of water to form a dispersion containing 3.81 parts by mass of ammonium dodecyl sulfate (ADS) as an anionic surfactant, with 2.32 parts by mass of mesoporous silica precursor 8 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which the template component had been extracted and removed from the mesoporous silica precursor. The state of the mesoporous silica precursor before extraction using the anionic surfactant was a cake with a high water content.

[0067] (Manufacturing Examples 13 and 11) Mesoporous silica precursor 3 in solution was recovered by filtration. Water and SDS were added to 100 parts by mass of water to form a dispersion containing 8.1 parts by mass of sodium dodecyl sulfate (SDS) as an anionic surfactant, with 5.84 parts by mass of mesoporous silica precursor 3 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. After that, it was washed with water, recovered, and dried to produce mesoporous silica from which the template component had been extracted and removed from the mesoporous silica precursor. The state of the mesoporous silica precursor before extraction using the anionic surfactant was a cake with a high water content.

[0068] (Manufacturing Examples 14 and 12) Mesoporous silica precursor 3 in solution was recovered by filtration. Water and ADS were added to 100 parts by mass of water to form a dispersion containing 7.27 parts by mass of ammonium dodecyl sulfate (ADS) as an anionic surfactant, with 5.50 parts by mass of mesoporous silica precursor 3 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. Subsequently, the mixture was repeatedly washed with an aqueous hydrochloric acid solution with a pH of 5 as washing water until the pH of the washing water reached 7.1, and then recovered and dried to produce mesoporous silica from which the template component had been extracted and removed. The state of the mesoporous silica precursor before extraction using the anionic surfactant was a cake with a high water content.

[0069] (Manufacturing Examples 15 and 13) Mesoporous silica precursor 3 in solution was recovered by filtration. Water and SDS were added to 100 parts by mass of water to form a dispersion containing 8.88 parts by mass of sodium dodecyl sulfate (SDS) as an anionic surfactant, with 5.83 parts by mass of mesoporous silica precursor 3 dispersed in the dispersion. The mixture was stirred at room temperature for 2 hours using a stirring blade. Subsequently, the mixture was repeatedly washed with an aqueous hydrochloric acid solution at pH 5 as washing water until the pH of the washing water reached 6.5, and then recovered and dried to produce mesoporous silica from which the template component had been extracted and removed. The state of the mesoporous silica precursor before extraction using the anionic surfactant was a cake with a high water content.

[0070] (Comparative Example 1) Mesoporous silica precursor 2 was recovered from the solution. A dispersion containing hydrochloric acid (27.85 parts by mass of water, 6.96 parts by mass of hydrogen chloride) in 100 parts by mass of ethanol, with 1.58 parts by mass of the mesoporous silica precursor dispersed in it, was stirred at room temperature for 3 hours. After that, it was washed with ethanol and recovered, and dried to produce mesoporous silica from which organic components had been extracted and removed from the mesoporous silica precursor. The state of the mesoporous silica precursor before extraction using a 20% 6M hydrochloric acid-ethanol solution was a dry powder.

[0071] [Removal of Mold Agent] (Comparative Example 2, Comparative Example 1) Mesoporous silica precursor 2 was recovered from the solution. After drying it at 160°C for 2 hours, the temperature was increased at a rate of 1°C / min and calcined at 600°C for 1 hour to obtain mesoporous silica. The state of the mesoporous silica precursor before calcination was a dry powder.

[0072] (Comparative Example 3, Comparative Example 2) Mesoporous silica precursor 3 was recovered from the solution. After drying it at 160°C for 2 hours, the temperature was increased at a rate of 1°C / min and calcined at 600°C for 1 hour to obtain mesoporous silica. The state of the mesoporous silica precursor before calcination was a dry powder.

[0073] (Comparative Example 4 of Manufacturing) Mesoporous silica precursor 3 in solution was filtered and recovered, and dried overnight at 100°C. The resulting mass was dry-ground using a Wonder Crusher WC-3L manufactured by Osaka Chemical Co., Ltd. to obtain a powder. A dispersion containing hydrochloric acid (23.05 parts by mass of water, 13.81 parts by mass of hydrogen chloride) in 100 parts by mass of ethanol, with 3.16 parts by mass of mesoporous silica precursor dispersed in it, was stirred at room temperature for 2 hours. After that, it was washed with ethanol, recovered, and dried to produce mesoporous silica from which organic components had been extracted and removed from the mesoporous silica precursor.

[0074] (Comparative Example 5 of Manufacturing) Mesoporous silica was prepared in the same manner as in Comparative Example 4, except that precursor 7 recovered from the solution was used.

[0075] (Comparative Example 6 of Manufacturing) Mesoporous silica was prepared in the same manner as in Comparative Example 4, except that precursor 8 recovered from the solution was used.

[0076] (Comparative Example 7, Comparative Example 3) After thoroughly drying the mesoporous silica of Comparative Example 1 at 160°C for 2 hours, 0.5 g was weighed out, and 60 ml of anhydrous hexane and 3-aminopropyltriethoxysilane were added, and the mixture was heated under reflux at 70°C for 6 hours. After washing with anhydrous hexane and acetone, it was dried.

[0077] (Specific Surface Area Measurement) The specific surface area of ​​the prepared mesoporous silica was measured using the multi-point method at liquid nitrogen temperature with a MicrotracBEL BELSORP MINI X and calculated using BJH calculation. The results are shown in Table 1-1.

[0078] (Measurement of silanol group content) <Measurement of silanol group content of 600°C calcined product> Mass M of mesoporous silica powder calcined at 600°C in Comparative Example 1 and Comparative Example 2 I The mass M was measured, then fired at 1000°C for 1 hour, and then measured again. II The mass decrease M at this time was measured. I -M II This is due to the dehydration of one water molecule from two silanol groups. I The amount of silanol groups per gram of 600°C calcined product was calculated by normalizing by mass. (M I -M II ) ÷ M I ÷18 [g / mol] × 2 × 1000 ...Silanol group amount 1 [mol / g] <Measurement of silanol group amount lost by 600°C> Approximately 10 mg of the mesoporous silica prepared in Example 2 and Example 4 was weighed out, and the mass change was measured from room temperature (25°C) to 600°C using a TGDTA7220 manufactured by Hitachi High-Tech Science Corporation. The heating rate was 5°C / min. Mass M at 350°C, when the burning of the hexadecyltrimethylammonium chloride, which is the template agent, is complete. III and the mass M at 600°C IV The following was read: Mass loss M at 350-600°C. III -M IVThis is the amount of silanol groups lost when calcined at 600°C. The amount of silanol groups lost during calcination is equal to the mass of mesoporous silica remaining at 600°C. IV The amount of silanol groups per gram of mesoporous silica after heating at 600°C was calculated using the standardization method. (M III -M IV ) ÷ M IV ÷18 [g / mol] × 2 × 1000 ...Silanol group amount 2 [mol / g] <Total silanol group amount> By adding silanol group amount 1 and silanol group amount 2, the amount of silanol groups 3 lost per gram of mesoporous silica after heating to 600°C during heating from 350°C to 1000°C can be calculated. Silanol group amount 1 + Silanol group amount 2 = Silanol group amount 3 By normalizing silanol group amount 3 [mol / g] by the mass before heating, the total silanol group amount [mol / g] of the mesoporous silica of Example 2 and Example 4 was calculated. Next, unit conversion was performed using specific surface area and Avogadro's number. Silanol group amount [units / nm] 2 ] = Silanol group amount [ mmol / g] ÷ Specific surface area [ m² 2 / g] × 10 -18 [nm 2 / m 2 ] × 6.02 × 10 23 [pcs / mol]×10 -3 [mol / mol] The total number of silanol groups in the mesoporous silica of Example 2 is 4.93 groups / nm. 2 The total number of silanol groups in the mesoporous silica of Comparative Example 1 was 2.67 groups / nm. 2 The total number of silanol groups in the mesoporous silica of Example 4 was 4.99 groups / nm. 2 The total number of silanol groups in the mesoporous silica of Comparative Example 2 was 2.61 groups / nm. 2 That was the case.

[0079] (Amino group content measurement) Approximately 10 mg of the mesoporous silica prepared in Manufacturing Example 7 was weighed out after drying at 100°C, and the mass change was measured from room temperature to 600°C using a TGDTA7220 manufactured by Hitachi High-Tech Science Corporation. The heating rate was 5°C / min. The mass M at 160°C, when the disappearance of amino groups begins. V And the mass M at 300°C, when the burning of the mold agent, ammonium dodecyl sulfate, begins. VI Furthermore, the mass loss M at 160-300°C V -M VI This is the amount of amino groups that are burned away. The amount of amino groups burned away is M from the initial mass. VII The amount of amino groups per gram of mesoporous silica was calculated by normalization. The amount of amino groups in the mesoporous silica of Production Example 7 was 1.03 mmol / g. (M V -M VI ) ÷ M VII ÷ 59 [g / mol] × 1000 ... Amino group amount [mol / g]

[0080] (Metal Content Measurement) After calcining the prepared mesoporous silica at 600°C for 2 hours, 50 mg was accurately weighed out and dissolved in 4 mL of hydrochloric acid. The concentrations of each metal (Cu, Al, Na) in the aqueous solution were then measured using an iCAP PRO XP Duo manufactured by Thermo Scientific. It is assumed that all metal components contained in the mesoporous silica dissolve in hydrochloric acid. Therefore, based on the measurement results, the content of each metal present in the mesoporous silica was calculated as the metal content. The results are shown in Table 1-2.

[0081] (Measurement of Extraction Rate) A 10 mg sample was weighed out and heated, and the mass change at each temperature was measured using a TG-DTA7220 manufactured by Hitachi High-Tech Science Corporation. The heating rate was 5°C / min. The mass M was measured at 160°C, when the evaporation of adsorbed water was complete. VIII And the mass M at 350°C when the burning of organic components is complete. IX The amount of organic components was determined from the mass M at 600°C. X The values ​​were standardized and expressed as the value per gram of product fired at 600°C. (M VIII -MIX ) / (M X ) ... Amount of organic components per gram of 600°C calcined product. This measurement determines the amount of organic components M contained in the mesoporous silica precursor. XI The amount of organic components M contained in mesoporous silica obtained by extracting and removing the template agent from the mesoporous silica precursor using a template extractant. XII The following was calculated, and the sampling rate was determined as follows. The results are shown in Table 1-1. Sampling rate = (M XI -M XII ) / M XI ×100 [%]

[0082] (Measurement of Ammonia Deodorization Rate) Ammonia gas at a concentration of 100 ppm was collected in a 500 mL flask using a permeator. 10 mg of prepared mesoporous silica was placed in the flask containing the gas, and after 15 minutes of deodorization, the ammonia concentration in the flask was measured using a detector tube, and the deodorization rate was calculated as follows. The results are shown in Table 1-2. Deodorization rate = (Initial ammonia concentration - Ammonia concentration after deodorization) / Initial ammonia concentration × 100

[0083] (Measurement of acetaldehyde deodorization rate) Acetaldehyde gas at a concentration of 14 ppm was collected in a 500 mL flask. 25 mg of prepared mesoporous silica was added to the flask containing the gas, and after 15 minutes of deodorization, the ammonia concentration in the flask was measured using a detector tube, and the deodorization rate was calculated as follows. The results are shown in Table 1-2. Deodorization rate = (Initial acetaldehyde concentration - Acetaldehyde concentration after deodorization) / Initial acetaldehyde concentration × 100

[0084] (Measurement of hydrogen sulfide deodorization rate) Hydrogen sulfide gas at a concentration of 18 ppm was collected in a 500 mL flask. 10 mg of prepared mesoporous silica was placed in the flask containing the gas, and after deodorization for 15 minutes, the hydrogen sulfide concentration in the flask was measured using a detector tube, and the deodorization rate was calculated as follows. The results are shown in Table 1-2. Deodorization rate = (Initial hydrogen sulfide concentration - Hydrogen sulfide concentration after deodorization) / Initial hydrogen sulfide concentration × 100

[0085] (Measurement of Methyl Mercaptan Deodorization Rate) Methyl mercaptan gas at a concentration of 8 ppm was collected in a 500 mL flask. 10 mg of prepared mesoporous silica was added to the flask containing the gas, and after 15 minutes of deodorization, the methyl mercaptan concentration in the flask was measured using a detector tube, and the deodorization rate was calculated as follows. The results are shown in Table 1-2. Deodorization rate = (Initial methyl mercaptan concentration - Methyl mercaptan concentration after deodorization) / Initial methyl mercaptan concentration × 100

[0086] (Measurement of moisture content) 0.5 g of the prepared mesoporous silica precursor was weighed out and dried in a dryer set to 100°C for 24 hours. The moisture content was determined from the change in mass before and after drying as follows. The results are shown in Table 1-1. Moisture content = (Mass of mesoporous silica precursor before drying - Mass of mesoporous silica precursor after drying) / Mass of mesoporous silica precursor before drying × 100

[0087]

[0088] (Confirmation of amino and urea groups) Mesoporous silica from manufacturing example 7 was measured by transmission using an FT-IR detector manufactured by JASCO Corporation (Figure 1). 1552 cm⁻¹ -1 , 1632cm -1 Since a peak corresponding to an amino group was observed, it was confirmed that amino groups were still present after extraction. Similarly, in the mesoporous silica of manufacturing example 12, which was measured, the result was 1568 cm⁻¹. -1 A peak corresponding to the urea group was confirmed. Elemental analysis was performed using approximately 10 mg of the sample with an oxygen circulation combustion / TCD detection NCH quantitative analyzer, Sumigraph NCH-22F type. The sample underwent pretreatment by vacuum drying at 100°C for 3 hours. The presence of amino groups was confirmed as Production Example 7 contained 4.83% nitrogen and Production Example 11 contained 1.86% nitrogen.

[0089] (X-ray diffraction measurement) The pore structure of the mesoporous silica was evaluated using an X-ray diffraction (XRD) apparatus (SmartLab, Rigaku Corporation). CuKα rays (λ = 0.15418 nm) were used in this measurement. The XRD pattern obtained for the mesoporous silica of Example 2 is shown in Figure 2. As shown in Figure 2, clear diffraction peaks indicating a regular pore structure due to the use of a template were confirmed. According to Bragg's formula, the mesoporous silica of Example 2 had peaks at 2.35°, 4.07°, and 4.67°, and the relative ratio of the diffraction angle peaks was 1:1.73:1.99, indicating a good hexagonal structure. Similar to Example 2, all examples of the present invention showed peaks in the diffraction angle range of 2 to 5°. From this, it was confirmed that the mesoporous silica of the present invention has a regular mesopore structure.

[0090] (Sample observation using a transmission electron microscope (TEM)) The pore structure of the mesoporous silica obtained in this invention was observed using a TEM (HITACHI HT7700). Samples were prepared by the following method: Approximately 0.5 mg of mesoporous silica was placed in an agate mortar, 1 mL of ethanol was added, and the silica was ground for 1 minute to prepare a fine powder suspension. The prepared suspension was dropped onto a TEM microgrid and dried at room temperature for approximately 3 minutes. After drying, it was confirmed that the solvent had completely evaporated, and the grid was loaded into the TEM for observation. As a result of the observation, it was confirmed that the mesoporous silica in all examples of this invention had a hexagonal structure.

[0091] (Evaluation of water dispersibility) 100 mg of the mesoporous silica prepared in Example 12 and Comparative Example 2 was weighed out, placed in a 2 mL centrifuge tube, 1 mL of water was added, and the mixture was shaken well to make it homogenized. Then, it was centrifuged at 500 rpm for 2 minutes to allow it to settle. The centrifuge tube containing the settled mesoporous silica was shaken up and down by hand about 10 cm. The number of shakes until the settled mesoporous silica was visually redispersed was counted. Each experiment was performed three times, and the average value was taken. In Example 12, it was 8 shakes, and in Comparative Example 2, it was 60 shakes. In other words, it was confirmed that the water dispersibility of the mesoporous silica of the present invention is greatly improved due to the high amount of silanol groups.

Claims

1. A method for producing mesoporous silica, comprising the steps of: (A) mixing a template agent and a silica raw material to form a mesoporous silica precursor; and (B) extracting the template agent from the mesoporous silica precursor using an aqueous solution containing a template extractant, wherein the template agent contains a cationic surfactant and the template extractant contains an anionic surfactant, or the template agent contains an anionic surfactant and the template extractant contains a cationic surfactant.

2. The manufacturing method according to claim 1, wherein step (A) comprises mixing at least one compound selected from the group consisting of water-soluble aluminum compounds, water-soluble iron compounds, aluminum alkoxides, and iron alkoxides with a mold agent and a silica raw material.

3. The manufacturing method according to claim 1 or 2, wherein step (A) comprises mixing at least one compound selected from the group consisting of water-soluble copper compounds, water-soluble zinc compounds, copper alkoxides, and zinc alkoxides with a template and a silica raw material.

4. Four silanol groups per unit surface area / nm 2 The above-mentioned mesoporous silica has a hexagonal structure and is metal-doped.

5. The mesoporous silica according to claim 4, wherein the metal is copper and is doped with 0.3% by mass or more of copper.

6. The mesoporous silica according to claim 4 or 5, further comprising an organic functional group that exhibits acetaldehyde deodorizing performance.

7. The mesoporous silica according to claim 4, paragraph 5, wherein the alkali metal content is 1.0% by mass or less.

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