JP2002001105A - Deodorizing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deodorizing composition for removing or reducing a bad smell component such as hydrogen sulfide and ammonia and a method for deodorizing to use the deodorizing composition. SOLUTION: This deodorizing composition contains titanium dioxide and iron hydroxide prepared from salt of trivalent iron.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a deodorizing composition for removing or reducing malodorous components such as hydrogen sulfide, ammonia, formalin, acetaldehyde, amines and mercaptans, and a deodorizing method using the same.

[0002]

2. Description of the Related Art Various methods have been proposed for removing and deodorizing malodorous components such as hydrogen sulfide, mercaptans, ammonia and aldehydes contained in air. Adsorption using activated carbon,
The deodorizing method is effective as one of the methods, but the deodorizing performance is not excellent for all the malodorous components, and there is a problem that the effect is remarkably reduced when the adsorption becomes saturated.

Japanese Patent Application Laid-Open No. Hei 10-43593 proposes a composite iron hydroxide containing α-iron hydroxide and γ-iron hydroxide as a hydrogen sulfide removing agent. Deodorizing ability is low for hydrogen sulfide, and deodorizing ability for hydrogen sulfide is not sufficient. Further, when preparing this composition, there is a problem that it is necessary to continue stirring and ripen the slurry of the hydroxide precipitate for 10 days.

On the other hand, many proposals have been made regarding the removal of offensive odor using a photocatalyst such as titanium dioxide. It utilizes the fact that titanium dioxide oxidizes and decomposes organic substances by light energy such as ultraviolet rays. However, the decomposition rate is relatively slow, and when the concentration of the malodorous component is high, the deodorizing effect is hardly obtained. In addition, when there is no light irradiation, the decomposition reaction does not occur.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve such problems, and as a result, have found that a composition containing iron hydroxide and titanium dioxide prepared from a trivalent iron salt has been developed. The present invention has been found to have high deodorizing performance and sustainability of deodorizing performance. That is, the present invention provides a deodorizing composition comprising iron hydroxide and tan dioxide prepared from a trivalent iron salt. The deodorizing power of conventional titanium dioxide utilizes photocatalytic performance, but the present invention exhibits high deodorizing performance without irradiation with light such as ultraviolet rays.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The trivalent iron salt in the deodorizing composition of the present invention may be any salt such as sulfate, nitrate, chloride, bromide, iodide and citrate. However, chloride salts are preferred. Iron hydroxide is prepared by adding an alkali while stirring an aqueous solution of a trivalent iron salt to increase the pH. The pH can be adjusted in the range of 4 to 13, and preferably 4 to 9. As the alkali to be added when preparing iron hydroxide, any of ammonia water, aqueous sodium hydroxide solution, aqueous potassium hydroxide solution and the like may be used, but sodium hydroxide is preferred. The concentration of iron salt in the aqueous solution is 1 to 100 g
/ L, but preferably 20 to 50 g / L.
L. It is considered that most of the iron hydroxide prepared from the trivalent iron salt is present as β-iron hydroxide, and partly changed to iron oxide after drying.

[0007] Titanium dioxide is anatase type, rutile type,
The brookite type may be used, but the anatase type is preferred. Generally, commercially available photocatalysts can be used.

[0008] As to the method of mixing iron hydroxide and titanium dioxide, a method of adding titanium dioxide powder to a slurry liquid prepared with iron hydroxide, followed by filtration, washing with water and drying is performed by adding titanium dioxide to an aqueous solution of a trivalent iron salt. After adding and dispersing the powder, p
A method of adjusting H to produce iron hydroxide, a method of mixing iron hydroxide powder and titanium dioxide powder, and the like are possible, and any method may be used. As a method for dehydrating the iron hydroxide slurry mixed with the iron hydroxide slurry or the titanium dioxide powder, any method such as a method using a suction filter or a centrifugal filtration device or a method of removing the supernatant after standing still may be used. Absent. The method and conditions for drying the mixed deodorizing composition are not particularly limited, but it is preferable to dry while heating at a temperature in the range of 50 to 150 ° C.
The mixing ratio of iron hydroxide and titanium dioxide is such that Fe: Ti is 1:
9-80: 20 is good, preferably 5: 95-50: 5
0 is good.

The deodorizing composition of the present invention can be used as a deodorant in the form of a powder itself. However, in the case of a powder, there is a problem of dusting in the handling, so that the powder may be used after granulation or use of metal or metal. It is also possible to use it by supporting or coating it on a substrate such as glass, ceramics, paper, plastic, and wood. When used as a coating agent, it can be mixed with a resin such as a binder. It is also possible to use a mixture of fillers such as alumina, talc, clay and calcium carbonate.

The malodor components removed by the deodorizing composition of the present invention include hydrogen sulfide, ammonia, formalin, acetaldehyde, amines, and mercaptans.

[0011]

The present invention will be described in more detail with reference to Examples and Test Examples, but the present invention is not limited by these.

[0012]

[Examples 1-3] Ferric chloride _(FeCl 3 · _6H 2 O)
20 g was dissolved in 400 g of distilled water. The pH of the solution in this case was about 1.5. Next, a pH of about 8.
An aqueous sodium hydroxide solution (10% by weight) was gradually added dropwise until the pH reached 5. A dark brown iron hydroxide precipitate slurry was obtained. After aging for 2 hours, it is filtered and put in a dryer at 110 ° C.
Let dry. After drying, it was pulverized using a mortar to obtain powdered iron hydroxide. This iron hydroxide and titanium dioxide for an anatase type photocatalyst (Tynoc A-100: manufactured by Taki Chemical Industry Co., Ltd.) were mixed at the weight ratio shown in Table 1 to obtain Examples 1 to 3.

[0013]

[Table 1]

[0014]

Example 4 Ferric chloride (FeCl ₃ .6H ₂ O) 20
g was dissolved in 400 g of distilled water. PH of the solution in this case
Was about 1.5. Next, a pH of about 7.0 was added to this solution.
An aqueous solution of sodium hydroxide (10% by weight) was gradually added dropwise until a slurry of a dark brown iron hydroxide precipitate was obtained.
Subsequently, titanium dioxide (Tynoc A-100 (anatase type) manufactured by Taki Chemical Industry Co., Ltd.) is added to the slurry liquid 62.
g was added thereto, and the mixture was sufficiently stirred. Then, a sodium hydroxide solution (10% by weight) was further added dropwise with stirring until the pH became about 8.5 to obtain a light brown precipitate. After aging for 2 hours, the precipitate was filtered by suction, washed with water and dried at 30 ° C. or lower. This is crushed in a mortar to 100 microns or less, and Fe and T
A powdered deodorizing composition in which i was mixed at a weight ratio of 1: 9 was obtained.

[0015]

Fifth Embodiment In Example 4, 28 g of titanium dioxide (Tynoc A-100 (anatase type) manufactured by Taki Kagaku Kogyo KK) was added, and Fe and Ti were similarly prepared.
Was obtained at a weight ratio of 2: 8 to obtain a powdery deodorizing composition.

[0016]

Example 6 A product prepared by adding 28 g of titanium dioxide (Tynoc A-100 (anatase type) manufactured by Taki Chemical Industry Co., Ltd.) in Example 4 was prepared, washed with water and dried in a drier at 110 ° C. The powder was pulverized to 100 microns or less in a mortar to obtain a powdery deodorizing composition in which Fe and Ti were mixed at a weight ratio of 2: 8.

[0017]

Comparative Example 1 Ferric chloride (FeCl ₃ .6H ₂ O) 20
g was dissolved in 400 g of distilled water. PH of the solution in this case
Was about 1.5. Next, a sodium hydroxide solution (10% by weight) was gradually added dropwise to the solution until the pH reached about 8.5, and a dark brown iron hydroxide precipitate slurry was obtained. After aging for 2 hours, the mixture was filtered and dried at room temperature. Put this in a mortar for 10
A powder was obtained by pulverizing the powder to 0 micron or less.

[0018]

Comparative Example 2 Ferric chloride (FeCl ₃ .6H ₂ O) 20
g was dissolved in 400 g of distilled water. PH of the solution in this case
Was about 1.5. Next, a sodium hydroxide solution (10% by weight) was gradually added dropwise to the solution until the pH reached about 8.5, and a dark brown iron hydroxide precipitate slurry was obtained. Subsequently, 63 g of zinc oxide was added to the slurry solution, and the mixture was sufficiently stirred. Then, while stirring a sodium hydroxide solution (10% by weight), the pH was dropped to about 8.5 to obtain a pale brown precipitate. Was. After aging for 2 hours, the precipitate was filtered off with suction.
It was dried at 0 ° C. or lower. This was ground in a mortar to 100 microns or less to obtain a powdery deodorizing composition in which Fe and Zn were mixed at a weight ratio of 1: 9.

[0019]

Comparative Example 3 A powdery deodorizing composition was prepared in the same manner as in Comparative Example 2 except that alumina powder was used instead of zinc oxide, and Fe and Al were mixed at a weight ratio of 1: 9. .

[0020]

Comparative Example 4 A powder of titanium dioxide (Tynoc A-100 (anatase type) manufactured by Taki Chemical Industry Co., Ltd.) was used as Comparative Example 4.

[0021]

Test Example 1 Powder 10 of Examples 1 to 5 and Comparative Examples 1 to 4
0 mg was placed in a 2500 ml glass Erlenmeyer flask, and sealed with a stoppered rubber stopper. Next, use a syringe to introduce 300 ppm of hydrogen sulfide gas into the Erlenmeyer flask.
Was injected so that One hour after this point, the concentration of hydrogen sulfide in the Erlenmeyer flask was measured using a hydrogen sulfide detector tube (manufactured by Gastec Corporation). The results are shown in Table 2.

[0022]

[Table 2]

[0023]

Test Example 2 Powder 1 of Examples 4 to 6 and Comparative Examples 1 and 4
00 mg was placed in a 2500-ml glass Erlenmeyer flask, and sealed with a stoppered rubber stopper. Next, use a syringe to introduce hydrogen sulfide gas into the Erlenmeyer flask at a concentration of 3000p.
pm. Periodically detects the concentration of hydrogen sulfide in an Erlenmeyer flask for water sulfide (Gastec Co., Ltd.)
If it was confirmed that the concentration was almost 0 ppm within 24 hours, the concentration was further increased to 3000 ppm.
The hydrogen sulfide gas was newly added so as to become. This was continued until the hydrogen sulfide gas concentration did not change, and the performance of removing the powder from hydrogen sulfide was determined. The results are shown in Table 3.

[0024]

[Table 3]

[0025]

Test Example 3 100 mg of the powders of Example 6 and Comparative Example 4 were placed in a 2500 ml glass Erlenmeyer flask and sealed with a rubber stopper with a stopcock. Next, hydrogen sulfide gas was injected into the Erlenmeyer flask using a syringe so as to have a concentration of 3000 ppm, and was placed indoors and outdoors (sunlight irradiation), respectively. From this point on, the concentration of hydrogen sulfide in the Erlenmeyer flask was measured at the point described in Table 4 using a detector tube (manufactured by Gastec Corporation). The results are shown in Table 4.

[0026]

[Table 4]

[0027]

The deodorizing composition of the present invention contains titanium dioxide and iron hydroxide, and easily and stably adsorbs malodorous components such as hydrogen sulfide, ammonia, formalin, acetaldehyde, amines and mercaptans for a long time. , Can be removed.

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Claims (5)

[Claims] 1. An iron hydroxide prepared from a trivalent iron salt and titanium dioxide in a weight ratio of Fe: Ti = 1: 99 to 80:20.
Deodorizing composition characterized by containing at a ratio in the range of 2. The deodorizing composition according to claim 1, comprising a composition prepared by mixing titanium dioxide with iron hydroxide prepared from a trivalent iron salt, dehydrating and washing with water. 3. A composition prepared by mixing titanium dioxide with iron hydroxide prepared from a trivalent iron salt, dehydrating and washing with water, and then heating and drying at a temperature of 50 to 150 ° C. or less. The deodorizing composition according to claim 1 or 2, wherein 4. A deodorizing method comprising using the deodorizing composition according to claim 1. 5. A deodorizing method comprising irradiating the deodorizing composition according to claim 1 with light.