Uses of metal-doped mesoporous silica

Abstract

To provide a method or the like for selectively deodorizing a malodor.SOLUTION: The present disclosure provides a method for using a metal-doped mesoporous silica that is doped with a metal, including the steps for (i) applying, spraying or mixing the metal-doped mesoporous silicate to an object and (ii) allowing a volatile component to contact the object or allowing the volatile component to generate from the object. The volatile component includes a non-malodorous component.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for using metal-doped mesoporous silica to selectively deodorize malodorous components. [Background technology]

[0002] Bad odors, such as those emanating from toilets, trash cans, and garbage dumps in homes and stores, and from waste liquids discharged from various factories, are a constant problem in people's lives. Generally, the odor-causing components are known to be basic odor-causing components such as ammonia and trimethylamine; acidic odor-causing components such as acetic acid and isovaleric acid; and sulfur-containing odor-causing components such as methyl mercaptan and hydrogen sulfide. Eliminating odors is important for a hygienic and comfortable life.

[0003] There are various deodorizers that use physical adsorption, chemical adsorption, and biological methods. Examples of deodorizers that use physical adsorption include porous inorganic materials such as activated carbon. Porous inorganic materials eliminate odorous components by encapsulating them within their pores.

[0004] In recent years, there has been a growing need to eliminate unpleasant odors and enjoy pleasant scents in daily life. Furthermore, as more people live with pets, there is also a growing need to eliminate bad odors while preserving odor components that humans cannot detect and compounds important to pets, such as pheromones. However, porous inorganic materials such as activated carbon cannot meet these needs because they also remove non-malodorous components, such as odor components other than bad odors and volatile components such as pheromones.

[0005] Patent Document 1 discloses porous silica doped with a metal X, which is Mn or Cu. The porous silica of Patent Document 1 can deodorize sulfur-containing odors with high efficiency and is applicable to applications such as deodorizers for permed hair and liquid deodorizers, but there is room for improvement in terms of selective deodorization, etc. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-15640 Summary of the Invention [Problem to be solved by the invention]

[0007] There is a need to establish a method for selectively eliminating malodors. [Means for solving the problem]

[0008] According to the present invention, the following is provided: [1] A method for using metal-doped mesoporous silica, which is doped with a metal, comprising the following steps: (i) applying, spraying or mixing the metal-doped mesoporous silica to a target; and (ii) A process in which a volatile component comes into contact with an object or a volatile component is generated from an object. Including, 10. The method of claim 9, wherein the volatile components comprise non-malodorous components. [2] The method of use according to [1] above, wherein the metal-doped mesoporous silica is contained in a deodorant product, and in step (i), the deodorant product is applied or sprayed onto a target. [3] The method of use described in [2] above, wherein the deodorant product is a fragrance-free deodorant product. [4] The method according to any one of the above [1] to [3], wherein the metal comprises at least one selected from the group consisting of copper, manganese, and cobalt. [5] The method of use according to any one of the above [1] to [4], wherein the volatile component comprises an olfactory stimulant capable of stimulating an olfactory receptor. [6] The method of use described in [5] above, wherein the olfactory stimulant includes an olfactory stimulant that can stimulate human olfactory receptors. [7] The method for use according to any one of the above [1] to [6], wherein the metal-doped mesoporous silica has a selective deodorizing property of 10 or more, as represented by the following formula: Selective deodorizing effect = (B1 + B2 + B3) / A In the formula, B1 represents the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is placed in a 500 ml container containing 1 μl of ammonia. B2 shows the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica was placed in a 500 ml container containing 1 μl of acetic acid. B3 shows the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica was added to a 500 ml container containing 2 μl of methyl mercaptan. A indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is added to a 500 ml container containing 2 μl of an aromatic component. [8] The method of use described in [7] above, wherein the aromatic component is at least one selected from the group consisting of limonene, pinene, cymene, terpinene, linalool, citral, ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, and terpineol. [9] The method of use according to the above [8], wherein the aromatic component is (R)-(+)-limonene.

[10] A deodorant product, characterized in that it contains metal-doped mesoporous silica doped with at least one element selected from the group consisting of copper, manganese, and cobalt, and is fragrance-free.

[11] The deodorant product according to the above

[10] , wherein the metal-doped mesoporous silica has a selective deodorizing property represented by the following formula of 10 or more. Selective deodorizing effect = (B1 + B2 + B3) / A In the formula, B1 represents the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is placed in a 500 ml container containing 1 μl of ammonia. B2 shows the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica was placed in a 500 ml container containing 1 μl of acetic acid. B3 shows the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica was added to a 500 ml container containing 2 μl of methyl mercaptan. A indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is added to a 500 ml container containing 2 μl of an aromatic component. [Effects of the Invention]

[0009] According to the present invention, a method for selectively deodorizing malodors is provided. DETAILED DESCRIPTION OF THE INVENTION

[0010] 1.How to use One embodiment of the present invention provides a method for using metal-doped mesoporous silica. The metal-doped mesoporous silica used in the present invention is porous silica doped with a metal. While it has high deodorizing properties for malodors, it has low deodorizing properties for odors other than malodors, such as aromatic components derived from perfumes. Therefore, it can selectively deodorize malodors without impairing pleasant fragrances. Furthermore, the metal-doped mesoporous silica used in the present invention has low adsorption and decomposition properties for volatile components other than odor components, such as pheromones, and therefore, in an environment where volatile components other than odor components are present, it can deodorize malodors while maintaining the volatile components.

[0011] In this specification, a volatile component refers to an organic compound present in the form of gas in the atmosphere and having a boiling point of 50 to 260°C. Examples of volatile components include olfactory stimulants that can stimulate the olfactory receptors of animals such as humans, pets, and livestock when they are exposed to them, i.e., odor components; and substances that are secreted or emitted by animals to the outside of their bodies and affect and change the behavior or physiological conditions of other individuals, i.e., pheromones. The volatile component is preferably an odor component, and more preferably an odor component that can stimulate the olfactory receptors of humans.

[0012] In this specification, odor components can be classified into malodorous components and other odor components. Malodorous components are components that stimulate the olfactory receptors of animals when they are smelled, causing discomfort to the animals. Examples of malodorous components include olfactory stimulants that have a structure containing at least one atom selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, and sulfur atoms and have a terminal functional group, or olfactory stimulants that have a structure containing a sulfur atom. The malodor component is preferably at least one component selected from the group consisting of basic malodor components, acidic malodor components, sulfur-containing malodor components, and aldehyde-based malodor components. Most preferably, it is at least one component selected from the group consisting of basic malodor components, acidic malodor components, and sulfur-containing malodor components. Examples of basic malodor components include ammonia and trimethylamine. Examples of acidic malodor components include acetic acid and isovaleric acid. Examples of sulfur-containing malodor components include methyl mercaptan, hydrogen sulfide, tert-butyl mercaptan, cysteamine, thioglycolic acid, cysteine, and thiazolidine. Examples of aldehyde-based malodor components include acetaldehyde, nonenal, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, and isovaleraldehyde.

[0013] <Metal-doped mesoporous silica> The method of this embodiment uses metal-doped mesoporous silica, which is porous silica that has been doped with a metal and has mesopores.

[0014] In metal-doped mesoporous silica, a metal is doped into the porous silica. "Doped" refers to a state in which the metal is incorporated into the silicon atom position within the SiO4 framework of the silica.

[0015] The type of metal to be doped (hereinafter sometimes referred to as metal X) may be selected depending on the type of malodorous component to be deodorized. Specific examples of metal X include copper, manganese, cobalt, zinc, silver, calcium, iron, etc. For example, when sulfur-containing malodorous components are to be deodorized, metal X is preferably copper, manganese, cobalt, or iron. When malodorous components having a fatty acid structure or aldehyde-based malodorous components are to be deodorized, metal X is preferably cobalt, zinc, silver, or calcium. Metal X may be one type of metal or multiple types of metals. Acidic and basic malodorous components can be deodorized by the doping metal, but can also be deodorized by the inherent effect of porous silica itself.

[0016] When multiple malodorous components are to be deodorized, metals may be selected for each malodorous component and the selected metals may be doped into the porous silica all at once. Alternatively, the selected metals may be doped into separate porous silicas to obtain multiple metal-doped mesoporous silicas, which may then be combined in an appropriate ratio.

[0017] The metal X is preferably at least one selected from the group consisting of copper, manganese and cobalt.

[0018] Doping porous silica with metal X can achieve a higher malodor-eliminating effect than when the metal X is present in granular form in the porous silica without being doped. This is thought to be because the doping causes the metal X to be present over the entire surface of the porous silica, resulting in a larger contact area between the malodorous components and the metal X. The term "present in particulate form" refers to a state in which the metal is supported by the porous silica without being doped.

[0019] Moreover, the metal-doped mesoporous silica used in the method of this embodiment not only has excellent malodor-eliminating properties, but also exhibits these excellent malodor-eliminating properties quickly.

[0020] Furthermore, when porous silica containing undoped metal X is used by mixing it into a liquid, there is a risk that metal X will elute into the liquid as metal ions. However, by doping the porous silica with metal X, it is possible to prevent metal X from being separated from the porous silica.

[0021] Furthermore, when the metal X is contained in the porous silica in a doped form, the color that would be observed if the metal X were present alone is reduced.

[0022] The content of the metal X in the metal-doped mesoporous silica is preferably 0.01 to 20 mass %, more preferably 0.01 to 10 mass %, and particularly preferably 0.1 to 5 mass %, from the viewpoint of the balance between the malodor-eliminating property and the ease of synthesis.

[0023] The metal-doped mesoporous silica preferably contains a metal different from the metal X. The metal different from the metal X may or may not be doped.

[0024] An example of a metal different from metal X is metal Y, which inhibits hydrolysis of porous silica. Metal Y is preferably a metal selected from the group consisting of aluminum and zirconium. Aluminum is particularly preferred. From the viewpoint of enhancing the hydrothermal durability of the metal-doped mesoporous silica, it is preferred that metal Y is also doped into the porous silica.

[0025] The content of metal Y in the metal-doped mesoporous silica is preferably 0.01 to 10 mass%, particularly preferably 0.1 to 5 mass%. If the content of metal Y is too low, the specific surface area may not be maintained during storage due to hydrolysis of the siloxane skeleton. If the content of metal Y is too high, a high specific surface area may not be achieved.

[0026] At least a part of the metal-doped mesoporous silica preferably has a chemical structure represented by the following formula 1. (Formula 1):SiO2·aXO b / 2 ·cYO d / 2 In Formula 1, X represents metal X. Y represents metal Y. a represents a number greater than 0 and equal to or less than 0.1. c represents a number greater than or equal to 0 and equal to or less than 0.1. b and d represent the valences of metal X and metal Y, respectively.

[0027] Preferably, at least a portion of the metal-doped mesoporous silica is irregular. Irregular shape means that the surface is multifaceted or rough and jagged. Irregular shape metal-doped mesoporous silica has the advantage of making it easier for the metal-doped mesoporous silica to adhere to targets (animals and articles, as described below).

[0028] The specific surface area of ​​the metal-doped mesoporous silica is set to 500m from the viewpoint of obtaining high deodorizing properties. 2 From the viewpoint of the strength required to maintain the pore structure, the upper limit of the specific surface area is 2000 m 2 / g or less. A more preferable specific surface area is 800 to 2000 m 2 / g, especially 800 to 1600m 2 / g.

[0029] The pore diameter of the metal-doped mesoporous silica is preferably 1 to 50 nm, and more preferably 2 to 10 nm from the viewpoint of enhancing selective deodorizing properties. The pore diameter can be measured by gas adsorption or small-angle X-ray scattering. Preferably, it can be measured by gas adsorption. More preferably, it can be determined by the BJH method from a nitrogen gas adsorption isotherm.

[0030] It is preferable to use metal-doped mesoporous silica having a selective deodorizing property represented by the following formula of 10 or more, with a property of 10 to 30 being particularly preferable. Selective deodorizing effect = (B1 + B2 + B3) / A B1 indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is placed in a 500 ml container containing 1 μl of ammonia. B2 shows the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica was placed in a 500 ml container containing 1 μl of acetic acid. B3 shows the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica was added to a 500 ml container containing 2 μl of methyl mercaptan. A indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is added to a 500 ml container containing 2 μl of an aromatic component. In this case, the aromatic component may be selected as desired, but is preferably at least one selected from the group consisting of limonene, pinene, cymene, terpinene, linalool, citral, ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, and terpineol. More preferably, it is at least one selected from the group consisting of (R)-(+)-limonene, ethyl butyrate, and α-terpineol. Particularly preferably, it is any one of (R)-(+)-limonene, ethyl butyrate, and α-terpineol. Most preferably, it is (R)-(+)-limonene.

[0031] The deodorizing amount of the metal-doped mesoporous silica (B1+B2+B3 in the formula showing the selective deodorizing property) is preferably 1 to 100 mmol / 1 g, and more preferably 10 to 100 mmol / 1 g.

[0032] The deodorizing amount of the metal-doped mesoporous silica (A in the formula showing the selective deodorizing property) is preferably 0.01 to 1 mmol / 1g, more preferably 0.1 to 0.5 mmol / 1g, and particularly preferably 0.1 mmol / 1g or more and less than 1.00 mmol / 1g.

[0033] In the metal-doped mesoporous silica, the ratio R represented by the following formula is preferably 3 or more, and particularly preferably 3 to 9. Ratio R=(B1+B2+B3) / (A1+A2+A3) B1 to B3 are the same as B1 to B3 in the formula showing the selective deodorizing property. A1 indicates the deodorizing amount (mmol / g) when 10 mg of a powder sample is placed in a 500 ml container containing 2 μl of (R)-(+)-limonene. A2 indicates the deodorizing amount (mmol / g) when 10 mg of powder sample is placed in a 500 ml container containing 2 μl of ethyl butyrate. A3 indicates the deodorizing amount (mmol / g) when 10 mg of a powder sample was placed in a 500 ml container containing 2 μl of α-terpineol.

[0034] A in the formula showing selective deodorizing properties and A1 to A3 in the formula showing the ratio R can be measured using an odor monitor (for example, the Handy Odor Monitor OMX-SR manufactured by Shinyei Technology Co., Ltd.). Specifically, a predetermined amount of fragrance component is placed in a 500 ml container, followed by 10 mg of metal-doped mesoporous silica. After one hour, the fragrance component remaining in the container is measured using the odor monitor. In the same manner, the fragrance component (blank) present in the container when no deodorant is used is measured. A and A1 to A3 are calculated by comparing with the blank measurement value.

[0035] B1 to B3 in the formula showing the selective deodorizing property and the formula showing the ratio R can be measured using a gas detection tube, as shown in the examples described later. Specifically, a predetermined amount of malodorous components is placed in a 500 ml container, and then 10 mg of metal-doped mesoporous silica is placed in it. After one hour, the concentration of the malodorous components remaining in the container is measured using a gas detection tube (for example, manufactured by Gastec), and B1 to B3 are calculated by comparing with the initial concentration.

[0036] The unit of deodorizing amount is mmol / 1g because, unlike other units such as ppm / 1g, it can eliminate the influence of molecular weight and makes it easier to compare the amount of deodorizing fragrance and the amount of deodorizing malodor.

[0037] Doping with metal X or metal Y is achieved by dissolving a water-soluble metal salt containing metal X or metal Y in a solvent and then mixing porous silica or its precursor with the resulting aqueous solution. To make at least a portion of the metal-doped mesoporous silica amorphous, amorphous porous silica or its precursor can be used as the raw material. Metal doping can be confirmed by measuring the chemical bonding state using X-ray photoelectron spectroscopy or Raman spectroscopy.

[0038] The metal-doped mesoporous silica can be preferably obtained by a method comprising the following steps: (A) A step of mixing a solvent, a surfactant, and a compound for doping with metal X containing metal X to prepare a surfactant solution. (B) A step of adding a silica source to a surfactant solution to generate micelles with the silica source accumulating on the surface. (C) A step of condensing the accumulated silica source. (D) After the condensation step, the micelles are recovered and calcined. Each step will be described in detail below.

[0039] (A): Preparation of surfactant solution First, a surfactant and a metal doping compound are added to a solvent to prepare a surfactant solution. The surfactant solution is preferably stirred at room temperature (usually 20°C) or higher and 200°C or lower for 30 minutes to 10 hours. This causes the surfactant to form micelles.

[0040] The solvent may be, for example, water, or a mixture of water and an organic solvent such as ethanol or toluene.

[0041] The amount of the surfactant added is preferably 50 to 400 mmol / L, more preferably 50 to 150 mmol / L, or preferably 0.01 to 5.0 mol, more preferably 0.05 to 1.0 mol per mol of the silica source added later.

[0042] The surfactant is not particularly limited, and cationic, anionic, and nonionic surfactants can be used. Preferably, the surfactant is neutral or cationic, and more preferably an alkylammonium salt. The alkylammonium salt preferably has 8 or more carbon atoms, and from the perspective of industrial availability, those with 12 to 18 carbon atoms are more preferred. 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. The surfactants may be used alone or in combination of two or more.

[0043] The metal X doping compound is a substance that serves as a supply source of the metal X to be doped into the porous silica. As the metal X doping compound, a water-soluble compound containing the metal X is preferred. More preferably, chlorides, nitrates, sulfates, etc. of the metal X are used.

[0044] For example, when the metal X is iron, iron(III) chloride or the like is added as a compound for doping the metal X. For example, when the metal X is copper, copper (II) nitrate, copper chloride, etc. are added as the metal X doping compound. For example, when the metal X is manganese, manganese(II) chloride or the like is added as a compound for doping the metal X. For example, when the metal X is cobalt, cobalt nitrate or the like is added as a compound for supplying the metal X. For example, when the metal X is zinc, zinc nitrate or the like is added as a compound for supplying the metal X. For example, when the metal X is silver, silver nitrate or the like is added as a compound for supplying the metal X. For example, when the metal X is calcium, calcium carbonate or the like is added as a compound for supplying the metal X. The metal X doping compounds may be used alone or in combination of two or more.

[0045] The amount of the metal X doping compound added is preferably 0.001 to 1 mol, more preferably 0.001 to 0.5 mol, and particularly preferably 0.01 to 0.1 mol, per mol of the silica source.

[0046] (B): Addition of silica source Subsequently, a silica source is added to the surfactant solution.

[0047] The silica source is not particularly limited as long as it can be used as a raw material for silica, and examples thereof include tetraethoxysilane, tetramethoxysilane, tetra-n-butoxysilane, and sodium silicate. These silica sources may be used alone or in combination of two or more. The silica source is preferably an alkoxysilane. The silica source is more preferably tetraethoxysilane. The organic functional groups on the silicon atoms are lost by hydrolysis and do not affect the structure of the synthesized product. However, if the organic functional groups are bulky, the hydrolysis rate may be slowed, which may result in a long synthesis time.

[0048] The amount of the silica source added is not particularly limited, but is preferably, for example, 0.2 to 1.8 mol / L. Alternatively, when the solvent contains water, the concentration of the silica source is preferably, for example, 0.001 to 0.05 mol per 1 mol of water.

[0049] (C): Condensation of silica source Next, the silica source is condensed. Specifically, the pH of the solution is increased or decreased until the silica source condenses. For example, the silica source can be condensed by adding a basic aqueous solution and stirring. The stirring is carried out, for example, for 1 hour or more, particularly 1 to 24 hours. By adding the basic aqueous solution, the silica source accumulated on the surface of the micelles is dehydrated and condensed to form a silica wall. Examples of basic aqueous solutions include aqueous solutions of sodium hydroxide, sodium carbonate, ammonia, etc. The basic aqueous solution is preferably an aqueous sodium hydroxide solution. These basic aqueous solutions may be used alone or in combination of two or more. The basic aqueous solution is added so that the pH immediately after addition is preferably 8 to 14, more preferably 9 to 11. The addition of the basic aqueous solution accelerates the dehydration condensation reaction of the silica source. As a result, the surface tension of the condensed portions increases, causing the silica walls to become spherical, and then the spheres become joined together in layers, causing spinodal decomposition (phase separation).These structures are frozen by chemical crosslinking.

[0050] The silica source has the property of condensing even at a low pH, and therefore, the silica source can be condensed by adding an acidic aqueous solution instead of a basic aqueous solution.

[0051] (D): Recovery and calcination of micelles Next, the micelles are recovered as a precursor from the aqueous solution. Specifically, when the silica source is condensed, micelles precipitate. The precipitate is then filtered off to recover the micelles as a precursor. The recovered precursor is dried. After drying, the precursor is calcined to remove organic components contained in the precursor. In other words, the surfactant that constituted the micelles is removed. This results in the formation of porous silica having pores. The calcination is carried out at a temperature equal to or higher than the decomposition temperature of the surfactant. The calcination temperature is, for example, 400 to 600°C.

[0052] By the above method, porous silica doped with metal X can be obtained. This method is one example, and the order of the steps may be changed, steps may be deleted, or new steps may be added. For example, in the above method, an example in which the metal X doping compound is added in step (A) has been described, but the metal X doping compound does not necessarily have to be added in step (A) and may be added to the solution at any stage before the calcination in step (D). If the accumulated silica source and the metal X doping compound are mixed in the solution, the metal X derived from the metal X doping compound is incorporated into the silica source, and porous silica doped with metal X is obtained.

[0053] Furthermore, when producing a metal-doped mesoporous silica containing metal Y in addition to metal X, a compound for doping with metal Y may be added at any stage prior to step (D). The compound for doping with metal Y is a substance that serves as a supply source of metal Y. As the compound for doping with metal Y, a water-soluble compound containing metal Y is preferably used. More preferably, chloride, nitrate, sulfate, etc. of metal Y are used.

[0054] For example, when the metal Y is aluminum, aluminum chloride or the like is added as a compound for doping the metal Y. For example, when the metal Y is zirconium, zirconium oxychloride or the like is added as a compound for doping the metal Y. The metal Y doping compounds may be used alone or in combination of two or more.

[0055] The amount of the metal Y doping compound added is, for example, preferably 0.001 to 0.5 mol, more preferably 0.01 to 0.1 mol, per 1 mol of the silica source.

[0056] The method of this embodiment uses the above-described metal-doped mesoporous silica and comprises the following steps: (i) applying, spraying or mixing metal-doped mesoporous silica to a target; and (ii) A process in which a volatile component comes into contact with an object or a volatile component is generated from an object. The order of the above steps (i) and (ii) is not particularly limited, and step (ii) may be performed after step (i), or step (ii) may be performed before step (i).

[0057] <Process (i)> In step (i), the metal-doped mesoporous silica, alone or in combination with other materials, is applied, sprayed, or mixed onto an object, such as a human, an animal such as a pet or livestock, or an article.

[0058] When the subject is an animal, in step (i), the metal-doped mesoporous silica may be applied or sprayed directly onto the animal, or may be applied or sprayed indirectly onto the animal by applying or spraying the metal-doped mesoporous silica onto something the animal is wearing or will wear. Examples of items worn by animals or items worn by humans include clothing, underwear, stockings, socks, shoes, accessories, bags, masks, diapers, etc.; and examples of items worn by pets and livestock include collars, clothing, tags, diapers, etc. Preferably, the metal-doped mesoporous silica is applied or sprayed directly onto a human, particularly human skin, or applied or sprayed onto something worn by a human, particularly clothing.

[0059] When applying or spraying the metal-doped mesoporous silica directly or indirectly onto an animal, the metal-doped mesoporous silica may be mixed with other materials to prepare a composition such as a liquid composition, a gel composition, or a powder composition containing the metal-doped mesoporous silica, and a deodorant product containing such a composition may be applied or sprayed.

[0060] Specifically, a composition containing metal-doped mesoporous silica may be blended as a deodorizer into a known deodorizer product that is applied or sprayed directly to an animal, or into a known deodorizer product that is applied or sprayed onto an animal's clothing or other items worn by the animal, and the metal-doped mesoporous silica may be applied or sprayed onto the target using such a deodorizer product. Examples of such deodorizer products include those in which the deodorizer is packed in a spray container (hereinafter sometimes referred to as a spray deodorizer product), those in which the deodorizer is packed in an aerosol can (hereinafter sometimes referred to as an aerosol deodorizer product), and sheet-type products, with spray deodorizer products and aerosol deodorizer products being preferred. Furthermore, fragrance-free deodorizer products are preferred as deodorizer products.

[0061] When the metal-doped mesoporous silica is used in a spray deodorant product, for example, the metal-doped mesoporous silica is mixed with any other additives in a solvent or dispersion medium such as water or alcohol, and the resulting composition is filled in a spray container, etc. By pointing the spray container at an animal and pulling the trigger, the metal-doped mesoporous silica is sprayed onto the animal.

[0062] Furthermore, when metal-doped mesoporous silica is used in an aerosol deodorant product, for example, the metal-doped mesoporous silica is mixed with any other additives in a solvent or dispersion medium such as water or alcohol, and the resulting composition is filled into an aerosol can or the like together with a propellant. Known propellants, such as LPG, DME, carbon dioxide, and HFC, can be used. When the aerosol can containing the composition is aimed at an animal and the spray button is pressed, the metal-doped mesoporous silica is sprayed onto the animal.

[0063] The content of metal-doped mesoporous silica in the composition is determined appropriately depending on the type of malodorous component to be deodorized, but is preferably 0.1 to 10 mass %, more preferably 0.5 to 2 mass %.

[0064] When metal-doped mesoporous silica is incorporated into a spray or aerosol deodorant product, a binder is preferably used as another additive to improve adhesion to the target. Examples of binders include urethane resins, acrylic resins, aminoplast resins, epoxy resins, glyoxal resins, and ethylene urea resins. Urethane resins and acrylic resins are preferred, with urethane resins being particularly preferred. As such urethane resins, polyurethane emulsions or water-soluble urethane resins are preferred. The amount of binder used can be determined appropriately depending on the composition of the composition, but is preferably 0.1 to 10% by mass per composition from the viewpoint of balancing ease of adhesion and ease of cleaning.

[0065] Alternatively, metal-doped mesoporous silica may be incorporated into known animal, particularly human, cosmetics, and then applied or sprayed onto animals. The cosmetics may be for any purpose, but are preferably hair (or fur, in the case of non-human animals), facial, fragrance, or body cosmetics. Examples of hair (or fur) cosmetics include shampoo, rinse, conditioner or treatment, hairspray, and hair wax. Examples of facial cosmetics include basic cosmetics such as cleansing cream, cold cream, massage cream, emulsion, lotion, serum, face mask, and makeup remover; and finishing cosmetics such as foundation, face powder, talcum powder, lipstick, lip balm, blush, eyeliner, mascara, eye shadow, eyebrow pencil, nail polish, and enamel remover. Examples of fragrance cosmetics include perfume, solid perfume, and fragrance powder. Examples of body cosmetics include body washes, body powders, deodorants (antiperspirants, etc.), bath additives, body lotions, sunscreens, hand creams, etc. It is preferable that the cosmetics are fragrance-free.

[0066] Next, the case where the target is an article will be described in detail. In the present invention, the metal-doped mesoporous silica can be applied to, sprayed on, or mixed with various articles that require deodorization of malodors. For example, the metal-doped mesoporous silica can be applied to or sprayed on furniture such as dressers and shoe cabinets; trash cans; home appliances such as refrigerators, freezers, and air conditioners; the inside of a car; storage spaces in homes such as closets and storage sheds; wet areas such as kitchen sinks and their drains, toilets and their drains, and bathtub and sink drains; and storage items such as clothing cases, food storage containers, and food storage bags. The metal-doped mesoporous silica can also be applied to or sprayed on fabrics such as futons, futon covers, cushions, blankets, carpets, curtains, sofas, air filters, air purifier filters, toilet seats, automobile floor mats and seats, and car air conditioner filters.

[0067] When applied or sprayed to an article, the metal-doped mesoporous silica may be contained as a deodorizer in a known deodorizer product. In this case, the metal-doped mesoporous silica may be included in a composition together with other materials as necessary. The deodorizer product is preferably a fragrance-free deodorizer product.

[0068] Known types of deodorant products may be used, such as deodorant products filled in spray containers, deodorant products filled in aerosol cans, and sheet-type deodorant products. When metal-doped mesoporous silica is blended into a spray deodorant product or an aerosol deodorant product, it is preferable to use a binder as another additive to improve adhesion to the target article. The type and amount of binder used are as described above.

[0069] Furthermore, metal-doped mesoporous silica may be mixed with other raw materials during the manufacture of target articles. Examples of such articles include furniture such as dressers and shoe cabinets; trash cans; home appliances such as refrigerators, freezers, and air conditioners; cars; household storage spaces such as closets and storage sheds; plumbing items such as kitchen sinks and their drains, toilets and their drains, and bathtub and sink drains; storage items such as clothing cases, food storage containers, and food storage bags; the aforementioned fabrics; fabric products such as fabric detergents, fabric softeners, and ironing agents; sheet or film products such as medical wrapping paper and film, food wrapping paper and film, freshness-preserving paper and film, wallpaper, tissue paper, toilet paper, garbage bags, and wet towels; food and beverage packaging containers; nursing care products such as portable toilets; and pet supplies. Preferably, metal-doped mesoporous silica is mixed with fabric or fabric products.

[0070] The article is preferably of the unscented type, which does not contain any fragrance.

[0071] <Process (ii)> In step (ii), the target is contacted with a volatile component or a volatile component is generated from the target. The volatile component includes non-malodorous components (volatile components other than malodorous components) such as pleasant scents (fragrant components) and pheromones.

[0072] Specifically, specific examples of step (ii) include, when the subject is a human, the human coming into contact with a pleasant scent by using a product that emits a pleasant scent, such as perfume, room fragrance, or shampoo; when the subject is an animal, the animal secreting pheromones; the use of scented products for pets or livestock; and, when the subject is an item, applying or spraying a product that emits a scent, such as an air freshener or perfume, to the item, or using a product that emits a scent near the item.

[0073] In the method of this embodiment, a subject (animal or article) is contacted with the metal-doped mesoporous silica in step (i) and with volatile components including non-malodorous components such as fragrance components and pheromones in step (ii). In other words, the subject comes into contact with the metal-doped mesoporous silica and the volatile components via separate routes and at separate times.

[0074] 2. Unscented deodorant products So far, the use of metal-doped mesoporous silica has been described as one embodiment of the present invention. However, as another embodiment, the present invention provides a deodorant product that contains metal-doped mesoporous silica doped with a metal, preferably at least one selected from the group consisting of copper, manganese, and cobalt, and is fragrance-free.

[0075] The deodorant product of this embodiment selectively deodorizes malodors without interfering significantly with non-malodor components such as fragrance components derived from perfumes and other volatile components such as pheromones. The characteristics, properties, and manufacturing method of the metal-doped mesoporous silica contained in the deodorant product of this embodiment are as described in Section 1. Method of Use.

[0076] The deodorizer product is also as described in Section 1. Method of Use. The deodorizer product of this embodiment also includes deodorizer products of the type that are used by means other than application or spraying, such as standing deodorizers.

[0077] The amount of metal-doped mesoporous silica contained in the deodorant product of this embodiment is preferably 0.1 to 10 mass %, more preferably 0.5 to 2 mass %. [Example]

[0078] Examples of the present invention will be described below, but the present invention should not be construed as being limited to these examples.

[0079] Example 1 Hexadecyltrimethylammonium chloride as a surfactant, copper chloride as a compound for doping with metal X, and aluminum chloride as a compound for doping with metal Y were added to water as a solvent and stirred at 100°C for 1 hour. After the aqueous solution was cooled to room temperature, tetraethoxysilane was added as a silica source and stirred. Next, sodium hydroxide was added as a condensation catalyst and stirred. The amounts of each compound added per mole of tetraethoxysilane were as follows: Surfactant (hexadecyltrimethylammonium chloride): 0.225 mol Metal X doping compound (copper chloride): 0.0204 mol Metal Y doping compound (aluminum chloride): 0.0482 mol Water: 125 moles Sodium hydroxide: 0.195 moles The solid product was filtered from the resulting suspension, dried, and then calcined to remove organic components, yielding metal-doped mesoporous silica. The resulting metal-doped mesoporous silica was designated as the powder sample of Example 1. The specific surface area of ​​the powder sample of Example 1 was 1100 m 2 The specific surface area and pore diameter were determined by the BJH method from the nitrogen gas adsorption isotherm at liquid nitrogen temperature.

[0080] <Comparative Example 1> Activated carbon powder (Kuraray Coal (registered trademark) GG) manufactured by Kuraray Co., Ltd. was prepared as a powder sample for Comparative Example 1.

[0081] <Comparative Example 2> Activated carbon powder (CAS RN: 7440-44-0) manufactured by Tokyo Chemical Industry Co., Ltd. was prepared as a powder sample for Comparative Example 2.

[0082] <Comparative Example 3> Mesoporous silica MCM-41 (CAS RN: 7631-86-9) manufactured by Sigma-Aldrich was prepared as a powder sample for Comparative Example 3. The specific surface area of ​​this powder sample was 894 m 2The specific surface area and pore size were determined by the BJH method from the nitrogen gas adsorption isotherm at liquid nitrogen temperature.

[0083] <Deodorizing properties> The following reagents were prepared as odor components: [Table 1]

[0084] Three 500 mL Erlenmeyer flasks were prepared, and the amount (μl) of (R)-(+)-limonene shown in the table below was dropped into each Erlenmeyer flask and allowed to volatilize. 10 mg of the powder samples from Example 1, Comparative Example 1, and Comparative Example 2 were added to each Erlenmeyer flask. After one hour, the amount of (R)-(+)-limonene in each Erlenmeyer flask was measured using an odor monitor (Handy Odor Monitor OMX-SR, Shinyei Technology Co., Ltd.). Similarly, the aromatic components (blank) present in the container when no deodorant was used were measured. The deodorizing amount of (R)-(+)-limonene was calculated by comparing the measured value with the blank value. Similarly, the deodorizing amounts of ethyl butyrate and α-terpineol were calculated.

[0085] Three 500 mL Erlenmeyer flasks were prepared, and the amount (μl) of ammonia shown in the table below was dropped into each Erlenmeyer flask and allowed to volatilize. 10 mg of the powder samples of Example 1, Comparative Example 1, and Comparative Example 2 were added to each Erlenmeyer flask. The amount of ammonia in each Erlenmeyer flask after one hour was measured using a gas detector tube (manufactured by Gastec). The amount of ammonia deodorized was calculated by comparing with the initial concentration. Similarly, the deodorizing amounts of acetic acid and methyl mercaptan were calculated. The amount of ammonia and acetic acid dropped was small so that the initial concentration would be similar to that of the other odor components. The results are shown in the table below. [Table 2]

[0086] The initial concentration (ppm) values ​​in the above table were calculated from the drop amount using the following formula.

number

[0087] The powder of Example 1 had a malodor eliminating property equal to or greater than that of the activated carbons of Comparative Examples 1 and 2.

[0088] In the Erlenmeyer flask to which the powder of Example 1 was added, significantly more aromatic components remained than in the Erlenmeyer flask to which the activated carbon of Comparative Examples 1 and 2 was added, and the aromatic deodorizing properties of the powder of Example 1 were lower than those of the activated carbon of Comparative Examples 1 and 2.

[0089] The selective deodorizing properties of the powders of Example 1, Comparative Example 1, and Comparative Example 2 were calculated based on the following formula. The results are shown in the table below. Selective deodorizing effect = (B1 + B2 + B3) / A In the formula, B1 represents the amount of ammonia deodorizing (mmol / g). B2 indicates the deodorizing amount of acetic acid (mmol / g). B3 indicates the deodorizing amount of methyl mercaptan (mmol / g). A indicates the deodorizing amount (mmol / g) of the aromatic component. [Table 3]

[0090] Based on the following formula, the ratio R of the total amount of malodor deodorizing to the total amount of fragrance deodorizing was calculated for the powders of Example 1, Comparative Example 1, and Comparative Example 2. The results are shown in the table below. Ratio R=(B1+B2+B3) / (A1+A2+A3) B1 to B3 have the same meaning as B1 to B3 in the formula showing the selective deodorizing property. A1 indicates the deodorizing amount (mmol / g) of (R)-(+)-limonene. A2 indicates the deodorizing amount (mmol / g) of ethyl butyrate. A3 indicates the deodorizing amount (mmol / g) of α-terpineol. [Table 4]

[0091] <Deodorizing speed> Two 500 mL Erlenmeyer flasks were prepared, and hydrogen sulfide gas was prepared in each Erlenmeyer flask using a permeator so that the initial concentration was 19 ppm. 10 mg of the powder samples of Example 1 and Comparative Example 3 were added to each Erlenmeyer flask. The amount of hydrogen sulfide in the Erlenmeyer flask after 5 minutes was measured using a gas detector tube (manufactured by Gastec). The results are shown in the table below. [Table 5]

[0092] The powder of Example 1 has a faster deodorizing rate than the powder of Comparative Example 3. Since there is no significant difference in the specific surface area and pore size between the powder of Example 1 and the powder of Comparative Example 3, it is believed that the faster deodorizing rate of the powder of Example 1 is due to the effect of the metal doping.

[0093] Considering the above various properties comprehensively, it was found that when the metal-doped mesoporous silica powder of Example 1 is used to deodorize animals or articles, it can selectively and quickly deodorize malodorous components without damaging non-malodorous components such as fragrance components and pheromones.

Claims

1. A method for using metal-doped mesoporous silica doped with 2 to 4 mass % of Cu and 2 to 5 mass % of Al, comprising the steps of: (i) applying, spraying or mixing the metal-doped mesoporous silica onto a target (excluding hair treated with a perm); and (ii) A step in which a volatile component comes into contact with an object or a volatile component is generated from the object. Including, the volatile components include non-malodorous components and at least one malodorous component selected from the group consisting of basic malodorous components, acidic malodorous components, and sulfur-containing malodorous components; The metal-doped mesoporous silica has a specific surface area of ​​800 to 1600 m 2 / g and a pore diameter of 2 to 10 nm.

2. The method of claim 1 , wherein the metal-doped mesoporous silica is contained in a deodorant product, and in step (i), the deodorant product is applied or sprayed onto the target.

3. 3. The method of claim 2, wherein the deodorant product is an unscented deodorant product.

4. The method of use according to any one of claims 1 to 3, wherein the volatile component comprises an olfactory stimulant capable of stimulating olfactory receptors.

5. The method of claim 4, wherein the olfactory stimulant comprises an olfactory stimulant capable of stimulating human olfactory receptors.

6. The method for using the metal-doped mesoporous silica according to any one of claims 1 to 5, wherein the metal-doped mesoporous silica has a selective deodorizing property of 10 or more, as represented by the following formula: Selective deodorizing property = (B １ +B ２ +B ３ ) / A In the formula, B １ indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is placed in a 500 ml container containing 1 μl of ammonia. B ２ indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is placed in a 500 ml container containing 1 μl of acetic acid. B ３ indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is placed in a 500 ml container containing 2 μl of methyl mercaptan. A indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is placed in a 500 ml container containing 2 μl of an aromatic component.

7. 7. The method of claim 6, wherein the aromatic component is at least one selected from the group consisting of limonene, pinene, cymene, terpinene, linalool, citral, ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, and terpineol.

8. The method according to claim 7, wherein the aromatic component is any one of (R)-(+)-limonene, ethyl butyrate, and α-terpineol.

9. The method of claim 8, wherein the fragrance component is (R)-(+)-limonene.

10. The method for use according to any one of claims 1 to 9, wherein the basic malodor component is at least one selected from the group consisting of ammonia and trimethylamine.

11. The method according to any one of claims 1 to 10, wherein the acidic malodor component is at least one selected from the group consisting of acetic acid and isovaleric acid.

12. The method according to any one of claims 1 to 11, wherein the sulfur-containing malodorous component is at least one selected from the group consisting of methyl mercaptan, hydrogen sulfide, tert-butyl mercaptan, cysteamine, thioglycolic acid, cysteine, and thiazolidine.

13. The method according to any one of claims 1 to 12, wherein the non-malodorous component is at least one selected from the group consisting of limonene, pinene, cymene, terpinene, linalool, citral, ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, terpineol, and pheromones.

14. A deodorant product characterized by containing metal-doped mesoporous silica that is doped with 2 to 4 mass % of Cu and 2 to 5 mass % of Al, has a specific surface area of ​​800 to 1600 m 2 / g, and has a pore diameter of 2 to 10 nm, and is fragrance-free.

15. The deodorant product according to claim 14, wherein the metal-doped mesoporous silica has a selective deodorizing property represented by the following formula of 10 or more. Selective deodorizing property = (B １ +B ２ +B ３ ) / A In the formula, B １ indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is placed in a 500 ml container containing 1 μl of ammonia. B ２ indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is placed in a 500 ml container containing 1 μl of acetic acid. B ３ indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is placed in a 500 ml container containing 2 μl of methyl mercaptan. A indicates the deodorizing amount (mmol / g) when 10 mg of metal-doped mesoporous silica is placed in a 500 ml container containing 2 μl of an aromatic component.

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