JP3528293B2 - Deodorant - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silica-based deodorant capable of effectively removing various unpleasant odors such as bad odors and offensive odors.

[0002]

2. Description of the Related Art Conventionally, various methods have been known as means for deodorizing and removing unpleasant odors. For example, a water washing method of dissolving a water-soluble gas component such as ammonia in water, a chemical solution absorption method of absorbing and decomposing with an acid, an alkali or an oxidizing agent,
Approximately 300-4 using a physical or chemical adsorption method using an adsorbent such as activated carbon or ion exchange resin, a direct combustion method in which combustion decomposition oxidation is performed at a temperature of 650 ° C. or higher, and a platinum catalyst.
Examples include a catalytic oxidation method in which oxidative decomposition is performed at 00 ° C., an ozone oxidation method in which oxidative decomposition by ozone is used in combination with masking, and a masking method in which a malodorous component is hidden by using an aromatic component.

Of these, the most widely used deodorizing method is a physical adsorption method using activated carbon. Usually, activated carbon is often used alone, but impregnated carbon obtained by impregnating and holding reactive components such as acid, alkali and catalyst component is also in practical use. Activated carbon is especially effective for removing low-concentration mixed odors, such as ventilation air in buildings and hospitals, odors generated from food processing processes, and odors generated from human waste and sewage treatment processes. It is widely used as a wide field.

As the adsorption type deodorant, in addition to activated carbon, zeolite, activated alumina, silica gel, or an inorganic carrier such as an oxidizing agent such as potassium permanganate, activated manganese dioxide or potassium chlorate, or sodium ascorbate, is used. It is known to carry a reducing agent such as a hypophosphoric acid compound.

[0005]

However, since the activated carbon is composed of a black carbonaceous material, it cannot be changed to another color tone, and in addition, oxidation consumption is promoted in a heated oxidizing atmosphere. There is a drawback that the range of use is limited. Moreover, although zeolite is excellent in selective adsorption to a specific pollutant gas, the open pores of the tissue are 3 to 20.
Since it has a micropore size of about angstrom, it has a drawback that it lacks the function of adsorbing and removing various kinds of malodorous components.

Activated alumina and silica gel are random aggregates of fine primary particles, and a wide range of pores ranging from micropores to macropores are distributed in the tissue, but their deodorizing function by themselves is not sufficient, and depending on the molding means. It is also extremely difficult to control the pore size within a certain range. Therefore, although it may be used as a carrier, its field of use as a deodorant is limited.

Recently, in addition to the industrial environment, various amenity products for improving the living environment have been demanded in accordance with the pursuit of a healthy and comfortable life, and the needs for deodorization and deodorization have increased. Therefore, the development of more functional deodorant is desired.

In view of such background, the inventors of the present invention have conducted various researches on a deodorizing material which has a high adsorption ability of activated carbon but does not have a defect peculiar to activated carbon. The present invention was developed by finding that mesoporous silica, which has not received attention, satisfies the above-mentioned required performance.

[0009] Incidentally, JP-A-6-24867 discloses a porous silica material containing a layered silicate such as kanemite as a raw material component, and has a property of adsorbing organic substances such as octane and combustion. However, the deodorant for the purpose of removing or decomposing malodorous gas has not been clarified.

It is an object of the present invention to provide a white silica-based deodorant which has a high adsorptive deodorizing ability for various malodorous gas components and can be stably used even in a high temperature oxidizing atmosphere.

The deodorant according to the invention for achieving the above object is based on active silica and a cationic surfactant.
The constitutional feature is that mesoporous silica obtained by firing the composite is used as an active ingredient.

Generally, mesopores mean a porous structure having an intermediate pore size between micropores and macropores, but the mesoporous silica according to the present invention is white and has an average pore size of 10 to 500 angstroms, preferably 20 to 200. It has a pore distribution of angstrom micropores or mesopores, and has a porous structure having a BET specific surface area (nitrogen adsorption specific surface area) of 800 m ² / g or more. The mesoporous silica structure of the present invention is composed of uniform pore cells, and the average diameter of the pore unit cells is determined by measuring the spacing d ₁₀₀ of the hexagonal structure (100) plane of the powder method X-ray diffraction pattern. , From this value [2d
₁₀₀ / √3] formula, and the average pore diameter can be determined by the nitrogen adsorption method.

The mesoporous silica according to the present invention has a low crystallinity, but the crystallinity is clearly recognized by X-ray diffraction. Therefore, the pore size of the mesopores forming the structure is excellent in uniformity. Further, since the mesoporous silica of the present invention is derived from activated silica or crystalline layered silicic acid, it has a significantly small Na content and is excellent in thermal stability as compared with the conventional porous silica. Is one.

The pore size and distribution of mesoporous silica can be arbitrarily adjusted at the production stage. The apparent fineness can be easily adjusted by pulverizing with a desired pulverizer, but it is important to note that excessive pulverization may destroy the structural structure of mesopores. As the deodorant according to the present invention, powdered mesorus silica can be used as it is, but the powder can also be used as an appropriate molded body. Further, it is possible to increase the deodorizing ability against malodorous substances by supporting a desired drug on these powders or molded articles according to the purpose of use.

Examples of the malodorous substances to be adsorbed by the deodorant according to the present invention include various sulfur compounds such as hydrogen sulfide, methyl sulfide, methyl mercaptan and ethyl mercaptan,
Basic nitrogen compounds such as ammonia, monomethylamine, dimethylamine and trimethylamine, aldehydes such as formaldehyde, acetaldehyde and propionaldehyde, carboxylic acids and derivatives such as butyric acid and isovaleric acid, indoles such as indole and skatole, phenols, Examples thereof include unsaturated hydrocarbons such as ethylene, alcohols such as isopropyl alcohol, sewage odor, animal odor, and human waste.

The means for producing porous silica, which is the active ingredient of the deodorant of the present invention, is not limited as long as it can impart the above-mentioned physical properties, but industrially, the following two methods are used depending on the type of silica source. Two methods are effective. First, the first method uses activated silica as a starting silica source. The first step is to prepare an activated silica by contacting an aqueous solution of sodium silicate with a cation exchange resin, and then the activated silica and a cationic surfactant are added. A second step of performing a mixed reaction in an alkaline region to form a complex of silica and a cationic surfactant,
This is a process of sequentially performing a third step of firing the composite.

The second method is to use a crystalline layered silicate as a starting silica source. The alkali metal ion in the crystalline layered silicate such as kanemite is ion-exchanged with a cationic surface active agent to form a cationic system. This is a process in which a first step of introducing a surfactant between layers, a second step of washing and removing alkali metal ions liberated by the ion exchange, and a third step of firing the composite are sequentially performed. Examples of the crystalline layered silicate that is selectively used as a starting material of the method include kanemite (NaHSi ₂ O ₅ .3H ₂ O), sodium disilicate (Na ₂ Si ₂ O ₃ ), and macatite (Na ₂ Si ₄ O ₉・ 5H ₂ O), islaite (Na ₂ Si ₈ O ₁₇・ XH ₂ O), magadiite (Na ₂ S
_{i 1 4 O 29 · XH 2} O), kenyaite _{(Na 2 Si 2 0 O 41} · XH 2 O) , etc. including without being limited thereto.

Further, as the cationic surfactant used in the above method, for example, a quaternary ammonium salt or an alkylamine salt is suitable. The quaternary ammonium salt is represented by the general formula [Rn (CH ₃ ) _4-n ] ⁺ [X] ^- (wherein
R is a long-chain alkyl group having 8 to 24 carbon atoms, n is an integer of 1 to 3, and X is a halogen or an OH group)
Is a primary alkyltrimethylammonium salt, and the alkylamine salt is represented by the general formula [RNH ₃ ] ⁺ [X] ⁻ (wherein R is the same long-chain alkyl group as described above, n is an integer of 1 to 3, X is halogen or OH). Which represents a group). By selecting these surfactants, the mesopore size of the mesoporous silica structure can be appropriately designed.

The calcination temperature in the calcination step is set to a temperature at which the surfactant component disappears, generally at a temperature of 500 ° C. or higher. Firing at a higher temperature is effective for stabilizing the structure of silica and improving mechanical strength.
If the temperature exceeds 00 ° C, it will not contribute to the stabilization of the structure and
Causes structural destruction. The firing time is appropriately set in relation to the treatment temperature, but is generally about 10 minutes to 1 hour. Therefore, a suitable firing condition is a firing temperature of 600 to 1200 ° C. and a firing time of 1 hour or less.

The deodorant according to the present invention can be prepared by molding mesoporous silica into a single powder or in the form of pellet, honeycomb or sphere. In the case of molding, a desired inorganic or organic binder is added to and mixed with mesoporous silica for molding. As the inorganic binder, for example, alumina sol, silica sol, silica-alumina sol or clays can be used. Examples of organic binders include polyvinyl alcohol, CMC,
Examples include MC, cyanoethylated starch, casein, sodium alginate, water-soluble polymers such as water-soluble cellulose derivatives, polyvinyl acetate latex, various synthetic resins such as SBR latex, and synthetic rubber latex. You may use these 1 type or in mixture of 2 or more types. The amount of these binders used with respect to mesoporous silica varies depending on the use form and is not particularly limited.

Further, in order to improve the deodorizing ability and to broaden the deodorizing gas spectrum, other inorganic fine powders may be used in combination if desired, or mesoporous silica powder or a molded body may be mixed with an alkali metal such as Li, Na or K. Alkaline agents such as hydroxides or carbonates, acidifying agents such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acidic aluminum phosphate, etc., alkali metal permanganates, chlorates, iodates, persulfates, Oxidizing agents such as ferrate, percarbonate, perborate, reducing agents such as alkali metal phosphite, hypophosphite, etc., as well as one or more agents such as colorants and fragrances. Good. Examples of the inorganic fine powder used in combination include alumina gel, silica gel,
Metal oxides such as titanate gel, zinc white, iron oxide, manganese dioxide, magnesium oxide, copper oxide, cuprous oxide and calcium oxide, or metal hydroxides such as hydrates thereof, magnesium silicate, calcium silicate, etc. Metal silicates, crystalline aluminosilicates such as zeolites, amorphous aluminosilicates (aluminosilicate is generally sodium silicate, but sodium may be replaced with other metal), etc. Examples include fine powder silicic acid. The deodorant thus obtained can be easily deodorized by filling or mounting it in a breathable bag, container, column or the like and allowing air containing a malodorous substance to pass through.

[0022]

The deodorant according to the present invention is characterized by containing mesoporous silica as an active ingredient. This mesoporous silica has a porous structure different from that of conventional silica, but is particularly porous and has an average pore diameter of 10
In the Mesopore range of ~ 500 Å, BE
It exhibits a high level of deodorizing ability when the T specific surface area is 800 m ² / g or more. Specific surface area value, for example, considerably greater than that of BET specific surface area of the silica gel or zeolite is in the range of approximately 200~600m ² / g, those having a specific surface area exceeding 800 m ² / g even at high activated carbon Since it is extremely rare, we can understand how large the surface activity is. It is speculated that such a unique pore structure exerts a wide range of excellent adsorption ability for various malodorous gas components contained in the atmosphere, and is effectively deodorized by the decomposition action of a strong solid acid. .

In addition, a Na content significantly smaller than that of the conventional porous silica is obtained by the manufacturing method, and this one has excellent thermal stability. Therefore, a stable deodorizing ability is maintained even under severe conditions of being heated in an oxidizing atmosphere, and there is no oxidative wear unlike activated carbon. In addition, the deodorant of the present invention can be used for a long period of time because it has a property of being adsorbed and decomposed depending on the target gas component, but when the adsorption capacity is reduced, it can be easily regenerated by heat treatment. You can

[0024]

EXAMPLES Examples of the present invention will be specifically described below in comparison with comparative examples.

Examples 1 to 4 , Comparative Examples 1 to 5 (1) Production Example of Mesoporous Silica-1 (Sample A); Hexadecyltrimethylammonium Cl salt (hereinafter referred to as "H").
7 kg of "DTMA-Cl") was added to 120 kg of water and stirred for 1 hour to dissolve HDTMA-Cl. Then, the dissolved slurry was passed through a column which was previously made into an OH ⁻ type and filled with an anion exchange resin (“Amberlite IRA-410”), and HDTM of pH 13 was passed.
150 Kg of A-OH aqueous solution was recovered. No. 3 sodium silicate (SiO ₂ ; 29.1%, Na ₂ O; 9.45%) 12
Kg was diluted with water to 120 Kg to make it a H ⁺ type cation exchange resin (“Amberlite IR-12”).
OB ″) was passed through a column to collect 125 Kg of an aqueous sol containing activated silica. This activated silica sol has a pH of 3.1 and the Na content in silica is 50 p.
It was pm. The above HDTMA-OH aqueous solution was stirred, to which active silica sol was added little by little, and the whole amount was mixed. The liquid became cloudy by mixing. The pH of the mixed slurry was 10.2.

Then, the mixed slurry is mixed at a temperature of 75.degree.
The mixture was stirred for a reaction for reaction and allowed to cool. The pH at this time was 10.2. The slurry was filtered, repulped to 100 liters, filtered again, and dried at a temperature of 120 ° C. When the obtained dry powder was subjected to X-ray diffraction,
The peaks of the pattern were observed at 2θ = 2.18 °, 3.74 ° and 4.20 °, and it was confirmed that the compound was a silica / surfactant complex.

The above dry powder was calcined at 650 ° C. for 30 minutes to burn off and remove the surfactant component. As a result of X-ray diffraction of the obtained fired product, 2θ = 2.34 degrees and 3.92
Shows a peak at 4.12 degrees and 4.12 degrees and has a mesoporous skeleton composed of uniform pore cells with an average pore cell diameter of 43.5 angstroms and an average pore diameter of 38.6 angstroms by the nitrogen adsorption method. It was recognized that Further, the specific surface area of the fired product by the BET method is 1
The content was 400 m ² / g and the Na content was 22 ppm.

[0028]

[0029]

(3) Deodorization test: The mesoporous silica powder (Sample A) obtained above was used as a deodorant, and a deodorization test was conducted using the following gases, which are typical malodorous gases. (1) Measurement of Removal of NH ₃ Gas 0.5 g of mesoporous silica powder was dispersed in a petri dish having a diameter of 8.5 cm, and left standing in a 10 liter Tedlar bag. Then, from inside the Tedlar bag,
The H ₃ gas was introduced and polluted, and the polluted air was sampled with time and measured by a gas tech detector tube to determine the concentration of the NH ₃ gas. Thus the results of the concentration over time changes in the NH ₃ in the resulting Tedlar bag which are shown in Table 1. _{(2) (CH 3)} 3 in place of N gas removal measuring NH ₃ gas using _{(CH 3) 3} N gas, others were measured in the same conditions as removal measurements of the NH ₃ gas. The results are also shown in Table 1. (3) butyric acid _{(C 3} H 7 COOH) instead removal of measured NH ₃ gas butyrate, others were measured in the same conditions as removal measurements of the NH ₃ gas. The results are also shown in Table 1. (4) Isovaleric Acid Removal Measurement Instead of NH ₃ gas, isovaleric acid [(CH ₃ ) ₂ CHC
[H ₂ COOH] was used, and the other conditions were measured under exactly the same conditions as the NH ₃ gas removal measurement. The results are also shown in Table 1.

As comparative examples, commercially available copper-substituted A-type zeolite, activated manganese dioxide, silica gel and activated carbon were similarly measured as deodorants, and the results are also shown in Table 1.

[0032]

[Table 1]

From the results shown in Table 1, it was confirmed that the examples using mesoporous silica as a deodorizing agent have a higher deodorizing ability for malodorous gas components than various commercially available deodorizing agents.

Example 5 Sample A on which NH ₃ gas was adsorbed in Example 1 was heated to 250 ° C.
After heating and regenerating for 30 minutes, the NH ₃ gas removal measurement was performed under the same conditions. The results of repeating this adsorption regeneration test are shown in Table 2.

[0035]

[Table 2]

Example 6 The mesoporous silica powder of sample A was dipped in a 3 wt% KIO ₃ solution and then dried to obtain a powder carrying KIO ₃ of about 0.35 wt%. When the formaldehyde removal measurement was performed on this sample by the same method as in Example 1,
The formaldehyde having a concentration of 16 ppm in the Tedlar bag was reduced to 2 ppm after 60 minutes, and it was confirmed that deodorization was substantially removed.

Example 7 Carboxymethyl cellulose solution 380 having a concentration of 0.5%
Parts by weight were added to 100 parts by weight of sample A and kneaded sufficiently. The kneaded product is extruded into a thin rod shape and
After drying at 0 ° C. for 2 hours, a cylindrical pellet having a diameter of 3 mm and a length of 3 to 7 mm was prepared. Obtained molded pellet 1
0.4 g was packed into a test column (25 mm diameter).
The height of the packed bed at this time was 63 mm. Then, trimethylamine was diluted with air to a concentration of 40 ppm and passed through. As a condition, the space velocity is 2000 / hr,
Gas flow rate 10 liter / min, surface wind speed 0.34 m / s
The temperature was set to ec, the temperature was 20 ° C., and the humidity was 50%. The inlet and outlet concentrations were measured by the gas detector tube method to determine the gas adsorption rate. The obtained relationship graph between the elapsed time and the adsorption rate is shown in FIG.

[0038]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a deodorant having a high deodorizing performance equivalent to or higher than that of activated carbon generally used as a conventional adsorption type deodorizing agent is provided by using mesoporous silica as an active ingredient. be able to. Moreover, since mesoporous silica is a white powder, it has excellent heat resistance, chemical stability, and safety, and because it is easy to regenerate, it has a wider range of applications than conventional deodorants such as activated carbon. It has the advantage of being significantly wider.

[Brief description of drawings]

FIG. 1 is a graph showing a gas adsorption rate of trimethylamine according to Example 9.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohiro Banda 9-15-1, Kameido, Koto-ku, Tokyo Inside the Research and Development Headquarters of Nippon Kagaku Kogyo Co., Ltd. (56) Reference JP-A-7-80296 (JP, A) JP-A-55-116615 (JP, A) JP-A-6-15165 (JP, A) JP-A-8-67578 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61L 9/00-9/22 B01D 53/34-53/96 B01J 20/00-20/34 C01B 33/00

Claims (3)

(57) [Claims] 1. Based on active silica and a cationic surfactant.
A deodorant characterized by using mesoporous silica obtained by firing a composite as described below as an active ingredient. 2. Mesoporous silica has an average pore size of 10
~ 500 Å, BET specific surface area 800 m ²
The deodorant according to claim 1, which has a particle property of not less than / g. Wherein the mesoporous silica is deodorizing agent according to claim 1 or 2, wherein the powder or molded body.