porous silica doped with various metals including high levels of copper

Abstract

The present invention provides a porous silica which exhibits an excellent deodorizing effect on a sulfur-containing odor. The porous silica of the present invention is a porous silica doped with a plurality of metals including copper, wherein the content of copper is 10 wt% or more. As the metal other than copper doped in the porous silica, iron, aluminum, and the like can be given.

Description

Technical Field

[0001] This invention relates to a porous silicon dioxide doped with multiple metals, including a high content of copper. Background Technology

[0002] As is well known, porous silica, due to its large specific surface area and micropore volume, is widely used in various fields as an adsorbent, humidifier, and catalyst carrier. In recent years, various attempts have been made to improve the functionality of porous silica. The inventors of this invention also reported in Patent Document 1, as one of their research results, that porous silica doped with manganese or copper (as metal X) exhibits a deodorizing effect on sulfur-containing odorous gases.

[0003] The inventors of this invention reported in Patent Document 1 that porous silica doped with manganese or copper as metal X is expected to be used as a material to eliminate sulfurous odors remaining in hair after perming treatments using sulfur-containing compounds such as cysteine ​​as reducing agents. However, in recent years, there has been a growing demand for porous silica with further improved performance.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-15640 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In view of this, the purpose of the present invention is to provide a porous silica that exhibits excellent deodorization effect on sulfur-containing odors.

[0009] Technical solutions for solving the problem

[0010] The inventors of this invention considered the above aspects and conducted in-depth research, and found that: doping porous silica with multiple metals, including high copper content, can achieve excellent deodorization effect on sulfur-containing odors, and the deodorization effect that deteriorates with use can be restored by washing with water.

[0011] Based on the above understanding, the porous silica of the present invention, in item 1 of the present invention, is a porous silica doped with multiple metals including copper, wherein the copper content is 10 wt% or more.

[0012] Furthermore, the porous silica in item 2 is that, in the porous silica described in item 1, the metal doped in the porous silica, other than copper, is selected from at least one of iron, aluminum, zirconium, cobalt, and manganese.

[0013] Furthermore, the porous silica in item 3 is that, in the porous silica described in item 1, the metal doped in the porous silica other than copper is iron and / or aluminum.

[0014] Furthermore, the porous silica in item 4 is that, in the porous silica described in item 1, the content of metals other than copper doped in the porous silica is 0.5 to 10 wt%.

[0015] Furthermore, in item 5, the deodorant of the present invention uses the porous silica described in item 1 as an active ingredient.

[0016] Invention Effects

[0017] According to the present invention, a porous silica that exhibits excellent deodorizing effect on sulfur-containing odors can be provided. Attached Figure Description

[0018] Figure 1 This is a graph showing the diffraction peak spectrum of the metal-doped mesoporous silica produced in Examples 1, 6, and Comparative Example 1. Detailed Implementation

[0019] The porous silica of the present invention is a porous silica doped with multiple metals, including copper, wherein the copper content is 10 wt% or more. In this specification, "metal-doped porous silica" refers to porous silica in which metals are incorporated through chemical bonding into the inorganic network of siloxane bonds constituting the porous silica.

[0020] In the porous silica of the present invention, the content of copper doped in the porous silica is 10 wt% or more, and the upper limit is, for example, 25 wt%.

[0021] Examples of metals other than copper that can be doped into porous silica include iron, aluminum, zirconium, cobalt, and manganese. These metals can be used alone or in combination of two or more. The content of metals other than copper doped into porous silica is, for example, 0.5 to 10 wt% (the total content of each metal when two or more metals are used in combination). When two or more metals are used in combination, the content ratio between the metals can also be, for example, 0.1 to 10 times the content of one metal compared to the content of the other metals.

[0022] The upper limit for the total amount of copper doped in porous silica, along with the amount of other metals, is, for example, 30 wt%. Porous silica doped with more than 30 wt% metals is difficult to manufacture.

[0023] As a porous silica, examples include mesoporous silica with a regular arrangement of fine pores (mesoporous pores) in diameter of 2 to 50 nm.

[0024] The specific surface area of ​​porous silica is, for example, 500–2000 m². 2 / g, which is preferred in terms of maintaining durability.

[0025] The manufacture of mesoporous silica doped with various metals, including copper at a content of 10 wt% or more, can be carried out according to the following methods, which are known in themselves, as described in, for example, Japanese Patent Application Publication No. 2020-15640.

[0026] (Process 1)

[0027] First, a surfactant and a raw material for doping mesoporous silica, including copper at a content of more than 10 wt%, are dissolved in a solvent and stirred at a temperature of, for example, 10 to 200°C for 0.1 to 10 hours, thereby causing the surfactant to form micelles.

[0028] The amount of surfactant dissolved in the solvent is, for example, 10 to 400 mmol / L, preferably 50 to 150 mmol / L. Alternatively, the amount of surfactant dissolved in the solvent is, for example, 0.01 to 5.0 mol, preferably 0.05 to 1.0 mol, relative to 1 mol of silica raw material added in step 2 described later.

[0029] As a surfactant, any of cationic, anionic, or nonionic surfactants can be used, but cationic surfactants such as alkylammonium salts are preferred. The alkylammonium salt is preferably an alkylammonium salt having an alkyl group having 8 or more carbon atoms; from the perspective of industrial availability, an alkylammonium salt having an alkyl group having 12 to 18 carbon atoms is more preferred. Specific examples of alkylammonium salts include hexadecyltrimethylammonium chloride, cetyltrimethylammonium bromide, stearyltrimethylammonium bromide, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, dodecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, octadecyltrimethylammonium chloride, didodecyldimethylammonium bromide, ditetradecyldimethylammonium bromide, didodecyldimethylammonium chloride, and ditetradecyldimethylammonium chloride. Surfactants can be used alone or in combination of two or more.

[0030] The amount of raw materials used to dope mesoporous silica, including copper at a content of 10 wt% or more, dissolved in a solvent (total amount of each raw material) is, for example, 0.001 to 0.5 mol, preferably 0.01 to 0.3 mol, relative to 1 mol of silica raw material added in step 2 described later.

[0031] Copper nitrate and copper chloride (either alone or in combination) are preferred as raw materials for copper doping. Ferric chloride is preferred as a raw material for iron doping. Aluminum chloride is preferred as a raw material for aluminum doping. Zirconium oxychloride is preferred as a raw material for zirconium doping. Cobalt nitrate is preferred as a raw material for cobalt doping. Manganese chloride is preferred as a raw material for manganese doping.

[0032] As a solvent, water can be used, for example. The solvent can also be a mixture of water and water-soluble organic solvents such as methanol, ethanol, diethylene glycol, and glycerol.

[0033] (Process 2)

[0034] Next, at, for example, room temperature, the silica raw material is dissolved in a solution in which the surfactant obtained in step 1 forms micelles, and the mixture is stirred until homogeneous, causing the silica raw material to aggregate on the surface of the surfactant micelles. The amount of silica raw material dissolved in the solution is, for example, 0.2 to 1.8 mol / L. Alternatively, when using water or a mixture of water and a water-soluble organic solvent as the solvent, the amount is, for example, 0.001 to 0.05 mol relative to 1 mol of water.

[0035] There are no particular limitations on the silica raw material as long as it can form an inorganic network composed of siloxane bonds that constitutes mesoporous silica through dehydration condensation. Specific examples of silica raw materials include tetraalkoxysilanes such as tetraethoxysilane, tetramethoxysilane, and tetran-n-butoxysilane, as well as sodium silicate. Tetraalkoxysilane is preferred, and tetraethoxysilane is more preferred. Silica raw materials can be used alone or in combination of two or more.

[0036] (Process 3)

[0037] Next, the silica raw material that has accumulated on the surface of the surfactant micelles undergoes dehydration and condensation to form an inorganic network composed of siloxane bonds constituting mesoporous silica, and various metals, including copper, are incorporated into the inorganic network through chemical bonding. The dehydration and condensation of the silica raw material can be achieved, for example, by adding an alkaline aqueous solution to the system to raise the pH value and then stirring at room temperature for more than 1 hour. The alkaline aqueous solution is preferably added in such a way that the pH immediately reaches 6 to 14, and more preferably in a way that the pH immediately reaches 8 to 12. If only an amount of alkaline aqueous solution that results in a pH below 6 is added, there is a risk that the dehydration and condensation of the silica raw material may be difficult to achieve, or that the metals, even if initially incorporated into the inorganic network, may redissolve. Specific examples of alkaline aqueous solutions include sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, sodium carbonate aqueous solution, and ammonia, but sodium hydroxide aqueous solution is preferred. Alkaline aqueous solutions can be used alone or in combination of two or more.

[0038] (Step 4)

[0039] Finally, the surfactant micelles obtained in step 3, which form an inorganic network on the surface constituting mesoporous silica composed of siloxane bonds and incorporating various metals, including copper, through chemical bonding, are filtered and recovered as precipitates. The precipitates are then dried at, for example, 30–120°C for 10–48 hours, and then calcined at 400–600°C for 1–10 hours to obtain mesoporous silica doped with various metals, including copper with a target content of 10 wt% or more. If the temperature rise from the drying temperature to the calcination temperature is rapid, metal oxide (e.g., copper oxide) particles will precipitate and mix in. Therefore, the heating rate is preferably 1°C / min or less, more preferably 0.5°C / min or less, and even more preferably 0.3°C / min or less. The resulting mesoporous silica doped with various metals, including copper with a content of 10 wt% or more, can also be pulverized as needed using a mixer, grinder, etc., to achieve a desired particle size (e.g., a median particle size of 0.01–100 μm).

[0040] It should be noted that the addition of raw materials, including copper with a content of more than 10 wt%, to the system for doping mesoporous silica is not limited to the method of dissolving in the solvent together with the surfactant in step 1 above. As long as the silica raw material is dissolved in the solution in step 2 or step 3 before the formation of the inorganic network composed of siloxane bonds constituting mesoporous silica is completed through dehydration condensation in step 3, it can also be used.

[0041] Alternatively, in step 2, instead of dissolving the silica raw material in the surfactant micelle solution obtained in step 1, a hydrolysis solution of the silica raw material prepared from the silica raw material and an aqueous solution of an inorganic acid (e.g., hydrochloric acid with a concentration of 0.001–0.1 M) can be added to the surfactant micelle solution.

[0042] Because the porous silica of the present invention not only contains copper at a content of 10 wt% or more, but also contains metals other than copper, it exhibits excellent deodorizing effects against sulfur-containing odors. Therefore, the porous silica of the present invention can be used as a material for eliminating sulfur-containing odors remaining in hair after perming treatments using sulfur-containing compounds such as cysteine ​​as reducing agents. Furthermore, after the porous silica of the present invention has exerted its deodorizing effect, it can be washed with water to restore the deterioration caused by use. Therefore, it can be molded into filter or granular shapes using methods known to exist, and thus can be reused.

[0043] Example

[0044] The present invention will be described in detail below through examples, but the present invention is not to be limited to the following description.

[0045] Example 1: Fabrication of mesoporous silica doped with 10 wt% copper and 5 wt% iron (Fabrication Example 1)

[0046] Copper chloride, used as a raw material for doping copper into mesoporous silica, and ferric chloride, used as a raw material for doping iron into mesoporous silica, were dissolved in water as a solvent. After stirring at room temperature for 30 minutes, tetraethoxysilane, used as a silica raw material, was further dissolved and stirred until homogeneous. This prepared solution was added to a solution prepared by dissolving hexadecyltrimethylammonium chloride, used as a surfactant, in water as a solvent and stirring at room temperature for 30 minutes, and then stirring at room temperature for another 30 minutes. Next, an aqueous solution of sodium hydroxide, used as an alkaline aqueous solution, was added so that the pH immediately after addition was 11.5, and the mixture was stirred at room temperature for 3.5 hours. The resulting precipitate was filtered and recovered, dried at 50°C for 24 hours, and then calcined at 500°C for 1 hour at a rate of 0.25°C / min, thereby obtaining the target substance as a green powder.

[0047] It should be noted that, relative to 1 mol of tetraethoxysilane as a raw material for silica, the amounts of hexadecyltrimethylammonium chloride as a surfactant, copper chloride as a raw material for doping copper into mesoporous silica, ferric chloride as a raw material for doping iron into mesoporous silica, and water (including water constituting the sodium hydroxide aqueous solution) as a solvent are as follows.

[0048] Hexadecyltrimethylammonium chloride: 0.225 mol

[0049] Copper chloride: 0.1202 mol

[0050] Ferric chloride: 0.0683 mol

[0051] Water: 125 mol

[0052] In addition, in order to prepare an aqueous solution of sodium hydroxide as an alkaline aqueous solution, 0.8 mol of sodium hydroxide was used relative to 1 mol of tetraethoxysilane, which is a raw material for silicon dioxide.

[0053] Example 2: Fabrication of mesoporous silica doped with 10 wt% copper and 5 wt% iron (Fabrication Example 2)

[0054] Hexadecyltrimethylammonium chloride (as a surfactant), copper chloride (as a raw material for doping copper into mesoporous silica), and ferric chloride (as a raw material for doping iron into mesoporous silica) were dissolved in water as a solvent. After stirring at room temperature for 30 minutes, tetraethoxysilane (as a silica raw material) was further dissolved and stirred until homogeneous. Next, an aqueous solution of sodium hydroxide (as an alkaline solution) was added so that the pH immediately after addition was 11.5, and the mixture was stirred at room temperature for 3.5 hours. The resulting precipitate was filtered and recovered, dried at 50°C for 24 hours, and then calcined at 500°C for 1 hour at a rate of 0.25°C / min, thereby obtaining the target material as a green powder. It should be noted that the amounts of hexadecyltrimethylammonium chloride as a surfactant, copper chloride as a raw material for doping copper into mesoporous silica, ferric chloride as a raw material for doping iron into mesoporous silica, tetraethoxysilane as a raw material for silica, sodium hydroxide, and water (including water constituting the sodium hydroxide aqueous solution) as a solvent are the same as those used in Example 1.

[0055] Example 3: Fabrication of mesoporous silica doped with 10 wt% copper and 5 wt% iron (Fabrication Example 3)

[0056] Tetraethoxysilane, used as a silica raw material, was dissolved in 0.01M hydrochloric acid and stirred until homogeneous to prepare a tetraethoxysilane hydrolysis solution. This hydrolysis solution was then added to a solution prepared by dissolving hexadecyltrimethylammonium chloride (as a surfactant), copper chloride (as a raw material for doping copper into mesoporous silica), and ferric chloride (as a raw material for doping iron into mesoporous silica) in water as a solvent and stirring at room temperature for 30 minutes. Next, an aqueous solution of sodium hydroxide, an alkaline solution, was added so that the pH immediately became 11.5, and the mixture was stirred at room temperature for 24 hours. The resulting precipitate was filtered and recovered, dried at 100°C for 24 hours, and then calcined at 500°C for 1 hour at a rate of 0.25°C / min, thereby obtaining the target material as a green powder. It should be noted that the amounts of hexadecyltrimethylammonium chloride as a surfactant, copper chloride as a raw material for doping copper into mesoporous silica, ferric chloride as a raw material for doping iron into mesoporous silica, tetraethoxysilane as a raw material for silica, sodium hydroxide, and water (including water constituting the sodium hydroxide aqueous solution and water constituting hydrochloric acid) as solvents used are the same as those used in Example 1.

[0057] Examples 4-10: Manufacturing of mesoporous silica doped with various amounts of copper, iron, and / or aluminum

[0058] Mesoporous silica doped with various amounts of copper, iron, and / or aluminum was prepared using the same method as that used in Example 1. It should be noted that aluminum chloride was used as the raw material for doping the mesoporous silica with aluminum.

[0059] Comparative Example 1: Manufacturing of mesoporous silica doped with only 15 wt% copper

[0060] It was manufactured using the same method as that used in Example 1.

[0061] Comparative Example 2: Manufacturing of mesoporous silica doped with only 5 wt% iron

[0062] It was manufactured using the same method as that used in Example 1.

[0063] Comparative Example 3: Manufacturing of mesoporous silica doped with only 2 wt% aluminum

[0064] It was manufactured using the same method as that used in Example 1.

[0065] Comparative Example 4: Manufacturing of mesoporous silica doped with 4 wt% copper and 5 wt% iron

[0066] It was manufactured using the same method as that used in Example 1.

[0067] Comparative Example 5: Manufacturing of mesoporous silica doped with 2 wt% copper and 2 wt% aluminum

[0068] It was manufactured using the same method as that used in Example 2.

[0069] Comparative Example 6: Manufacturing of mesoporous silica doped with 8 wt% copper and 2 wt% aluminum

[0070] It was manufactured using the same method as that used in Example 1.

[0071] Table 1 summarizes the metal-doped mesoporous silicon dioxide produced in Examples 1-10 and Comparative Examples 1-6.

[0072] [Table 1]

[0073]

[0074] It should be noted that the specific surface area and pore diameter were determined using a Microtrac BEL BEL MAX II instrument with a multi-point method to measure the adsorption isotherm of nitrogen at liquid nitrogen temperature, and calculated using BJH calculations. The fact that the mesoporous silica is doped with metal was confirmed by analysis using an X-ray diffraction (XRD) apparatus (Rigaku Corporation SmartLab), based on the absence of diffraction peaks originating from undoped metals in the mesoporous silica (i.e., diffraction peaks of metal oxide particles generated, precipitated, and mixed with undoped metals in the mesoporous silica). For example, the diffraction peak spectra of the copper- and iron-doped mesoporous silica produced in Example 1, the copper- and aluminum-doped mesoporous silica produced in Example 6, and the copper-doped mesoporous silica produced in Comparative Example 1 are shown below. Figure 1 In the diffraction peak spectra of the copper- and iron-doped mesoporous silica produced in Example 1 and the copper- and aluminum-doped mesoporous silica produced in Example 6, there are no diffraction peaks originating from copper that has not been doped into the mesoporous silica (i.e., diffraction peaks of copper oxide particles generated, precipitated, and mixed in by copper that has not been doped into the mesoporous silica) present in the diffraction peak spectra of the copper-doped mesoporous silica produced in Comparative Example 1.

[0075] As shown in Table 1, the diffraction peaks of the copper- and iron-doped mesoporous silica produced in Example 4 and the copper- and aluminum-doped mesoporous silica produced in Example 7 do not contain the diffraction peaks originating from copper that were not doped into the mesoporous silica, which were present in the diffraction peak spectrum of the copper-doped mesoporous silica produced in Comparative Example 1. This means that in Example 4, since iron was doped along with copper, and in Example 7, since aluminum was doped along with copper, a copper content of 15 wt% was achieved in each case. However, in Comparative Example 1, where neither iron nor aluminum was doped with copper, a copper content of 15 wt% was not achieved in the mesoporous silica. Therefore, when copper with a content of 10 wt% or more is doped into mesoporous silica, by doping it with metals other than copper, such as iron or aluminum, it is possible to avoid the formation and precipitation of copper oxide particles from copper that has not been doped into the mesoporous silica and their mixing in the mesoporous silica.

[0076] Evaluation Experiment 1: Deodorization effect of metal-doped mesoporous silica prepared in Examples 1-10 and Comparative Examples 1-6 on hydrogen sulfide.

[0077] (Experimental Methods)

[0078] In a 30 mL polypropylene (PP) container, 0.2 g each of the metal-doped mesoporous silica prepared in Examples 1-10 and Comparative Examples 1-6, 19.8 mL of water, and 26.4 g of alumina spheres with a diameter of 2 mm were added, and the mixture was wet-milled at 250 rpm for 2 hours to prepare a slurry. 1 mL of the prepared slurry was uniformly dropped onto 50 mg of silica wool and dried at 160°C for 1 hour to prepare silica wool with a surface treated with metal-doped mesoporous silica. Two of the prepared silica wools with a surface treated with metal-doped mesoporous silica were uniformly filled into a 1 cm diameter Teflon (registered trademark) tube, bringing the total length to 2 cm. A tube filled with silica wool surface-treated with metal-doped mesoporous silica was filled with 18 ppm hydrogen sulfide generated by a permeation gas generator (Gastec PD-1C, hereinafter the same). Odor gas was collected at the outlet every 3 minutes, and the concentration of hydrogen sulfide in the odor gas was measured using detection tubes (Gastec 4LK, 4LB, 4L, hereinafter the same, as appropriate). This measurement was continued until the concentration of hydrogen sulfide in the odor gas exceeded 9 ppm (i.e., the deodorization rate was less than 50%), and the total amount of hydrogen sulfide adsorbed by the metal-doped mesoporous silica up to this point was calculated. The deodorization capacity was calculated by dividing the total amount of adsorbed hydrogen sulfide by the amount of metal-doped mesoporous silica carried by the silica wool, and the deodorization effect of metal-doped mesoporous silica on hydrogen sulfide was evaluated. It should be noted that the total amount of hydrogen sulfide adsorbed by the metal-doped mesoporous silica is calculated by converting 3L of the hydrogen sulfide concentration calculated using the formula "18ppm - ((hydrogen sulfide concentration at the start of the 3-minute count + hydrogen sulfide concentration at the end of the 3-minute count) / 2)" into mass and then accumulating the results. (In the first measurement, the "hydrogen sulfide concentration at the start of the 3-minute count" is 18ppm; in subsequent measurements, the "hydrogen sulfide concentration at the start of the 3-minute count" is the same as the "hydrogen sulfide concentration at the end of the 3-minute count" from the previous measurement). The amount of metal-doped mesoporous silica carried by the silica wool is calculated by subtracting the weight of the two untreated silica wool (100mg) from the weight of the two silica wool wools that have undergone surface treatment with metal-doped mesoporous silica.

[0079] (Experimental Results)

[0080] The results are shown in Table 2. As can be clearly seen from Table 2, the metal-doped mesoporous silica produced in Examples 1 to 10, by doping with copper at a content of more than 10 wt% and also doping with iron and aluminum, which are metals other than copper, exhibits excellent deodorization effect against hydrogen sulfide. The mesoporous silica doped only with copper produced in the comparative examples had a poor deodorization effect against hydrogen sulfide. As mentioned above, this is believed to be due to the generation and precipitation of copper oxide particles from copper that was not doped into the mesoporous silica, which then mixed into the mesoporous silica. However, by doping iron and aluminum with copper as metals other than copper, the generation, precipitation, and mixing of copper oxide particles were avoided, thereby significantly improving the deodorization effect against hydrogen sulfide (for example, the deodorization effect of the mesoporous silica doped with copper and iron produced in Example 4 and the mesoporous silica doped with copper and aluminum produced in Example 7 was more than 4 times that of the mesoporous silica doped only with copper produced in Comparative Example 1). This was an unexpected result for the inventors of the present invention.

[0081] [Table 2]

[0082]

[0083] Evaluation Experiment 2: The effect of water washing performed to restore the deodorizing effect of the metal-doped mesoporous silica produced in Examples 1-10, which had deteriorated with use.

[0084] (Experimental Methods)

[0085] In 200 mL flasks, 1 g each of the metal-doped mesoporous silica prepared in Examples 1-10 was added. Hydrogen sulfide gas at 18 ppm, prepared by a permeation gas generator, was passed through the flasks at a flow rate of 1 L / min overnight, allowing the metal-doped mesoporous silica to adsorb the hydrogen sulfide. During this period, the flasks were shaken every few hours to stir the metal-doped mesoporous silica, ensuring that the hydrogen sulfide was distributed throughout all the silica and adsorbed. The following morning, the concentration of hydrogen sulfide in the odorous gas in the flasks was measured every few hours using a detection tube. The flasks were deemed to have reached their deodorization point when the hydrogen sulfide concentration remained unchanged. The metal-doped mesoporous silica was then recovered from the flasks, placed in 300 mL of pure water, and washed with water by stirring at 500 rpm for 3 hours. Finally, it was recovered by vacuum filtration. After the recovered metal-doped mesoporous silica was dried at 160°C for 1 hour, the deodorization capacity was calculated according to the evaluation method used in Evaluation Experiment 1. Furthermore, 10–20 mg of metal-doped mesoporous silica before and after water washing was accurately weighed, and 8 mL of 2M hydrochloric acid was added. The solution was heated at 120°C for 1 hour to dissolve the silica. Then, ultrapure water was added to bring the volume to 250 mL. The sulfur concentration in the final solution was measured using an inductively coupled plasma optical emission spectrometer (ICP-OES, Thermo Scientific). Based on the measurement results, the sulfur content of the metal-doped mesoporous silica before and after water washing was calculated.

[0086] (Experimental Results)

[0087] Therefore, it can be seen that the deodorizing effect of the metal-doped mesoporous silica produced in Examples 1-10, which deteriorates with use, can be restored by washing with water. The deodorizing capacity after washing is, for example, 13.8 μg / mg for the mesoporous silica produced in Example 1 doped with 10 wt% copper and 5 wt% iron, and 11.9 μg / mg for the mesoporous silica produced in Example 6 doped with 10 wt% copper and 2 wt% aluminum. Both are higher than the deodorizing effect of the unused mesoporous silica produced in Comparative Example 1 doped only with 15 wt% copper (8.3 μg / mg according to Table 2). Furthermore, for example, the mesoporous silica doped with 10 wt% copper and 5 wt% iron produced in Example 1 had a sulfur content of 1.6 wt% before water washing and a sulfur content of 0.6 wt% after water washing, indicating that 63% of the sulfur content before water washing was desorbed. Although the mechanism by which the metal-doped mesoporous silica produced in Examples 1 to 10 exhibits this effect is not fully understood, the inventors of this invention believe that it is possible that the metal-doped mesoporous silica produced in Examples 1 to 10, for example, has a hydrophilic surface, which allows the water used for washing to easily desorb the hydrogen sulfide adsorbed at the hydrogen sulfide adsorption sites, thereby regenerating or reforming the hydrogen sulfide adsorption sites, resulting in the restoration of the deteriorated deodorization effect.

[0088] Examples 11-18: Manufacturing of mesoporous silica doped with varying amounts of copper and iron

[0089] Mesoporous silica doped with copper and iron in the same manner as in Example 1 was manufactured. Its deodorizing effect on hydrogen sulfide was evaluated according to the method of Evaluation Experiment 1. At the same time, the water washing effect used to restore the deodorizing effect that deteriorated with use was evaluated according to the method of Evaluation Experiment 2. As a result, the mesoporous silica doped with copper and iron manufactured in each example had the same effect as the mesoporous silica doped with copper and iron manufactured in Examples 1, 4 and 5.

[0090] (Example 11) Copper content: 11 wt%, Iron content: 5 wt%

[0091] (Example 12) Copper content: 12 wt%, Iron content: 5 wt%

[0092] (Example 13) Copper content: 13 wt%, Iron content: 5 wt%

[0093] (Example 14) Copper content: 14 wt%, Iron content: 5 wt%

[0094] (Example 15) Copper content: 16 wt%, Iron content: 5 wt%

[0095] (Example 16) Copper content: 17 wt%, Iron content: 5 wt%

[0096] (Example 17) Copper content: 18 wt%, Iron content: 5 wt%

[0097] (Example 18) Copper content: 19 wt%, Iron content: 5 wt%

[0098] Examples 19-29: Fabrication of mesoporous silica doped with various amounts of copper and aluminum

[0099] Mesoporous silica doped with copper and aluminum in the following amounts was manufactured using the same method as in Example 1. Its deodorizing effect against hydrogen sulfide was evaluated according to Evaluation Experiment 1, and its water washing effect to restore the deodorizing effect deteriorated with use was evaluated according to Evaluation Experiment 2. The results showed that the mesoporous silica doped with copper and aluminum manufactured in each example had the same effect as the mesoporous silica doped with copper and aluminum manufactured in Examples 6 and 7. It should be noted that aluminum chloride was used as the raw material for doping aluminum into the mesoporous silica.

[0100] (Example 19) Copper content: 10 wt%, Aluminum content: 5 wt%

[0101] (Example 20) Copper content: 10 wt%, Aluminum content: 8 wt%

[0102] (Example 21) Copper content: 11 wt%, Aluminum content: 2 wt%

[0103] (Example 22) Copper content: 12 wt%, Aluminum content: 2 wt%

[0104] (Example 23) Copper content: 13 wt%, Aluminum content: 2 wt%

[0105] (Example 24) Copper content: 14 wt%, Aluminum content: 2 wt%

[0106] (Example 25) Copper content: 16 wt%, Aluminum content: 2 wt%

[0107] (Example 26) Copper content: 17 wt%, Aluminum content: 2 wt%

[0108] (Example 27) Copper content: 18 wt%, Aluminum content: 2 wt%

[0109] (Example 28) Copper content: 19 wt%, Aluminum content: 2 wt%

[0110] (Example 29) Copper content: 20 wt%, aluminum content: 2 wt%.

[0111] Industrial practicality

[0112] This invention has industrial applicability in providing a porous silica that can effectively deodorize sulfur-containing odors.

Claims

1. A porous silica, characterized in that: The porous silica is porous silica doped with multiple metals, including copper, with a copper content of 10 wt% or more.

2. The porous silica according to claim 1, characterized in that: The metal doped into porous silica, other than copper, is selected from at least one of iron, aluminum, zirconium, cobalt, and manganese.

3. The porous silica according to claim 1, characterized in that: The metals other than copper that are doped into porous silica are iron and / or aluminum.

4. The porous silica according to claim 1, characterized in that: The content of metals other than copper doped in porous silica is 0.5 to 10 wt%.

5. A deodorant, characterized in that: The deodorant uses the porous silica described in claim 1 as its active ingredient.

Images