JPH0642900B2 - Deodorant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a sulfur-based malodorous substance such as hydrogen sulfide, mercaptan, methyl sulfide, and methyl disulfide in the atmosphere or gas and a nitrogen-based malodorous substance such as ammonia or amines. The present invention provides a deodorant that efficiently adsorbs a substance together with the substance without being affected by moisture, and in particular, a deodorant having an excellent adsorption ability when used at room temperature and dry type.

[Conventional technology]

The presence of malodorous substances in the atmosphere and gas has become a social problem as pollution. The bad odor not only makes the living environment unpleasant, but has also become a serious problem affecting health. Recently, complaints about the unpleasant odor have been increasing with the improvement of living standards.

As is well known, as the deodorizing method, there are a cleaning method using an acid / alkali aqueous solution, a direct combustion method, a catalytic oxidation method, an adsorption method and the like. However, the cleaning method using an acid / alkali aqueous solution is difficult to treat and maintain the deodorizing waste liquid, and the direct combustion method and the catalytic oxidation method require a large amount of air to be burned at a high temperature and generate sulfur dioxide gas. Treatment of nitrogen oxides is also required and is not an advantageous method.

For these, an adsorption method that is relatively simple and can be used at room temperature is drawing attention, and there is a strong demand for the development of a deodorant having an excellent ability to adsorb malodorous substances in gas.

The air and gas contain, as malodorous substances, sulfurous malodorous substances such as hydrogen sulfide, mercaptan, methyl sulfide, and methyl disulfide, and nitrogenous malodorous substances such as ammonia and amines. Is accompanied by. Heretofore, various deodorants suitable for sulfur-based malodorous substances and nitrogen-based malodorous substances have been proposed.

Ferric hydrated ferric oxide, iron oxide, zinc oxide and the like are known as deodorizers for sulfur malodorous substances, but their ability to adsorb nitrogen malodorous substances is insufficient.

Further, as a deodorant for nitrogen-based malodorous substances, silica / alumina-based adsorbents, solid acids such as zeolite, inorganic acids such as sulfuric acid and phosphoric acid on carriers such as clays and porous substances, oxalic acid and citric acid. It is known to carry organic acids and the like, but these have a problem that they are easily affected by moisture accompanying an odorous substance.

In particular, with regard to solid acids such as silica-alumina-based adsorbents and zeolite, the water entrained in the malodorous substance causes the moisture to be preferentially adsorbed to the solid acid, and the adsorption of the nitrogenous malodorous substance is reduced, resulting in a sufficient adsorption capacity. There is a problem that it cannot be demonstrated.

This fact is, for example, "Fragrance, Journal"
(No.72, 1985) Page 75, "... Silica / alumina-based adsorbents have an affinity for odorous substances with strong basicity or polarity, but water adsorbed in gas adsorbs them strongly. Adsorption of odorous substances is hindered. Zeolite also shows different adsorption affinity for a wide variety of odorous molecules depending on the size of the molecule, but in the presence of water, deodorization is hindered as in the former case. ........ ”

That is, a solid acid such as a silica / alumina-based adsorbent or theolite has a reduced adsorption ability due to the influence of water. In addition, the deodorant carrying an inorganic acid or an organic acid causes corrosion of the deodorant storage container or deodorizing device due to the elution of the inorganic acid or organic acid carried because the clay or porous substance adsorbs water. There is a danger that it will occur, and there is a problem in handling.

On the other hand, as a deodorant that adsorbs both sulfur-based malodorous substances and nitrogen-based malodorous substances, an inorganic acid and an oxidizing agent such as potassium permanganate are added to a carrier such as activated carbon or clays or porous substances. It is known to be carried by the above method.

However, it has been pointed out that the adsorption capacity of activated carbon is insufficient.

This fact is explained, for example, in "Fragrance Journal" (No. 72, 1985), page 75, "... General-purpose activated carbon, basic gas such as ammonia, amine, hydrogen sulfide, acidic gas such as mercaptan, or sulfurization. It has a low adsorption capacity for neutral gases such as methyl and aldehyde .... "

In addition, when a carrier such as clay or a porous substance is supported by adding an inorganic acid and an oxidizing agent, since the clay or the porous substance adsorbs water, the supported inorganic acid or oxidizing agent is eluted. There is also a problem that the adsorbing ability is lowered and the eluted acid solution corrodes the storage container and the deodorizing device.

Sulfur-based malodorous substances such as hydrogen sulfide, mercaptan, methyl sulfide, and methyl disulfide are acidic or neutral gases, and nitrogen-based malodorous substances such as ammonia and amines are basic gases. Therefore, the deodorizing agent to be adsorbed differs depending on the malodorous substance, as described above.

In particular, many of the deodorants that adsorb nitrogen-based malodorous substances and many of the deodorant substances that adsorb both malodorous substances together use clays or porous substances as carriers, so the adsorption of malodorous substances due to water interference Not only is the performance deteriorated, but the elution of the loaded inorganic acid and oxidant also poses a handling risk.

Also, in order to absorb both malodorous substances without being affected by moisture, a moisture adsorbent, a sulfur type malodorous substance deodorant, and a nitrogen type malodorous substance deodorant are combined and adsorbed in multiple stages. However, there is a problem in that the storage of the deodorant becomes complicated and requires a large volume.

[Problems to be Solved by the Invention]

In view of the above problems, the present invention efficiently adsorbs sulfur-based malodorous substances and nitrogen-based malodorous substances together without being affected by moisture, and does not involve the risk of handling, particularly at room temperature / dry type. It is a technical object to provide a deodorant having an excellent adsorption capacity when used.

[Means for solving problems]

The present inventor has arrived at the present invention as a result of systematic studies and studies for the purpose of solving the above technical problems.

That is, the present invention has a bamboo-like hydrous second oxide having a stripe-shaped ultrafine structure and having a major axis diameter of 0.2 to 1.0 μm and an axial ratio (major axis diameter / minor axis diameter) of 3 to 10. It is a deodorant composed of a mixed powder of iron particle powder 30 to 60% by weight and solid acid powder 40 to 70%.

[Work]

First, the most important point in the present invention is that the axial ratio (major axis diameter / major axis diameter) is 0.2 to 1.0 μm, which has a stripe-shaped ultrafine structure.
(Short axis diameter) 3 to 10 bamboo-leaf-shaped ferric hydroxide-containing fine powders that adsorb sulfur malodorous substances,
Due to preferentially adsorbing the accompanying water, the solid acid is not affected by the water, and the nitrogen-based malodorous substance can be effectively adsorbed by the acid property of the powder of the solid acid. Efficiently adsorbs both sulfur and nitrogen malodorous substances in the air and gas without being affected by moisture, and does not pose a danger of handling, especially when used at room temperature and dry type Is also a fact that can be done efficiently.

The ferric hydroxide-containing fine particle powder used in the present invention is a bamboo grass having a streaky ultrafine structure and a major axis diameter of 0.2 to 1.0 μm and an axial ratio (major axis diameter / minor axis diameter) of 3 to 10. Since it is a leaf-shaped particle, it has a very large specific surface area.Because it is a rounded particle, the particles do not stick to each other so that they do not overlap with each other, resulting in a large porosity and good air permeability. Due to the large contact area with
Compared to acicular hydrous ferric oxide particles, sulfur-based malodorous substances can be efficiently adsorbed.

Further, hydrous ferric oxide particle powder used in the present invention is not affected by moisture in the atmosphere or gas, therefore,
Even when accompanied by water, the ability to adsorb malodorous substances does not decrease.

The fact that generally hydrous ferric oxide particles is less susceptible to moisture, for example, Chemical Society of Japan published "Journal of the Chemical Society of Japan" (1980) "...... hydrated iron oxide of the 681 pages is SO ₂ chemisorption since found that the high capacity for the purpose of considering the possibility as SO ₂ adsorbent material, subjected to SO ₂ adsorption experiment from a gas mixture close to the combustion furnace exhaust gas composition, H ₂ SO ₂ adsorption capacity coexisting Knowing that it is hardly affected by O,
"..." is as described.

That is, it is a deodorant for a sulfur malodorous substance which has an extremely excellent adsorption ability such that the adsorption efficiency of the sulfur malodorous substance does not change at all even when the moisture accompanying the malodorous substance is adsorbed.

INDUSTRIAL APPLICABILITY The deodorant of the present invention preferentially adsorbs water entrained in the atmosphere or gas by using a powder of ferric hydroxide-containing fine particles in the shape of bamboo leaves having an extremely excellent ability to adsorb sulfur malodorous substances. Therefore, the sulfur-based malodorous substance and the nitrogen-based malodorous substance in the atmosphere or gas are not affected by the influence of moisture on the powder of the solid acid which is extremely excellent in the adsorption ability of the nitrogen-based malodorous substance. It is a deodorant that is both efficient without being affected by, and has excellent adsorption ability when used at room temperature and dry type without any danger of handling.

Next, various conditions for carrying out the present invention will be described.

The ferric hydroxide-containing fine particle powder used in the present invention has a striped ultrafine structure, has a length of 0.2 to 1.0 μm, and has an axial ratio (major axis diameter / minor axis diameter) of 3 to 10 It is a powder consisting of ferric oxide hydroxide particles exhibiting the above.

Particles having a major axis diameter of more than 1.0 μm are unsuitable because they have a small specific surface area, and particles having a major axis diameter of less than 0.2 μm are undesirably agglomerated between particles because they are too fine.

In addition, particles with an axial ratio of less than 3 have a smaller characteristic that the particles have a bamboo-like shape with a stripe-shaped ultrafine structure, and particles with an axial ratio of more than 10 have a needle-like shape. It is not preferable.

The ferric oxide hydroxide fine particle powder used in the present invention can be easily obtained by the following production method.

That is, 1 equivalent or more of an aqueous solution of an alkali carbonate with respect to the ferrous salt is added to the ferrous salt aqueous solution and reacted to obtain FeCO ₃ , and an oxygen-containing gas is passed through the obtained suspension containing FeCO ₃ . Then, it is obtained by an oxidation reaction.

In the above production method, as the aqueous ferrous salt solution, an aqueous ferrous sulfate solution, an aqueous ferrous chloride solution, or the like is used. When an aqueous solution of ferrous salt or an aqueous solution of alkali carbonate or an alkali hydroxide is added to an aqueous solution of ferrous salt to obtain FeCO ₃ or Fe-containing precipitate, a part of the alkali carbonate is treated with alkali hydroxide within a range of 50% or less with respect to the alkali carbonate. You may replace and use it.
As the alkali carbonate, sodium carbonate, potassium carbonate,
When ammonium hydrogencarbonate or the like is used alone or in combination with alkali hydroxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide or the like is used. Further, in some cases, it may be aged under a non-oxidizing atmosphere.

The pH of the solution during the oxidation reaction is 7-11. If the pH is less than 7 or exceeds pH ₁₁ , bamboo hydroxide-like ferric oxide particles cannot be obtained.

The reaction temperature during oxidation is 30 to 80 ° C. When the temperature is lower than 30 ° C, bamboo-leaf-shaped ferric oxide hydroxide particles cannot be obtained, and when the temperature exceeds 80 ° C, granular black precipitates are mixed.

The oxidizing means is performed by aerating an oxygen-containing gas (for example, air) in the liquid, and is performed while stirring by the aeration gas or mechanical operation.

The solid acid powder used in the present invention is a well-known substance, and it is possible to use a solid exhibiting acid properties such as acid clay, bentonite, kaolin, deer / alumina, silica magnesia, silica boa, and synthetic zeolite. .

Further, a super strong acid obtained by bringing zirconium hydroxide into contact with sulfuric acid and firing it can also be used.

When used in the deodorant of the present invention, a clay mineral or zeolite having no acidity is brought into contact with hydrochloric acid, nitric acid or the like to give Na ⁺
The ions K ⁺ ions may be replaced to form solid acids as H ⁺ ions.

Unlike the case where an inorganic acid is supported, solid acid has an acid property that is produced by subjecting a substance having a cation exchange ability to an ion exchange treatment, so it is safe to handle without elution with water. is there.

Next, the method for producing the deodorant of the present invention is extremely simple,
The target substance can be obtained by blending powdery ferric oxide hydroxide having a bamboo leaf shape with a powder of a solid acid in a required ratio and mixing them with a mixer of a wet method or a dry method. In addition, you may dry as needed.

Further, the deodorant of the present invention may be used by being granulated and used as it is in a powder form or a pellet form, or may be mixed or applied to paper or cloth and formed into a honeycomb structure or a laminated structure for use. You can also Further, it can be attached to a substrate having a honeycomb structure or a laminated structure and used as a deodorizing filter.

The deodorant of the present invention has a mixing ratio of bamboo leaf-shaped ferric hydroxide-containing fine powder and solid acid powder of the deodorant of 30 to 60% by weight of bamboo leaf-shaped ferric hydroxide-containing fine powder. The acid powder is 40 to 70% by weight, preferably the bamboo leaf-shaped ferric oxide hydroxide fine powder is 40 to 50% by weight, and the solid acid powder is 50 to 60% by weight.

30% by weight of powdered ferric oxide hydroxide powder in the shape of bamboo leaves
When the amount is below, the ability to adsorb sulfur malodorous substances is lowered, and the solid acid is affected by moisture, which is not preferable.

If the solid acid powder content is less than 40% by weight, the ability to adsorb nitrogenous malodorous substances is reduced, which is not preferable.

〔Example〕

 Next, the present invention will be described with reference to examples.

Example 1 Bamboo leaf-shaped ferric hydroxide fine powder having a leaf shape (major axis diameter 0.25 μm determined from electron micrograph, axial ratio (minor axis diameter / minor axis diameter) 8, specific surface area 106 m determined by BET method ² g) and 25 g of a commercially available HY-type zeolite (TSZ-320H manufactured by Toyo Soda Kogyo Co., Ltd.) were dry-mixed to prepare a deodorant 1 having a mixing ratio of 50% by weight: 50% by weight.

Deodorizing agent 1 and a commercially available deodorizing agent (activated carbon (A)) as a comparative sample were respectively pressure-molded and broken into frames to produce 10 to 20me.
About 0.4 g of sh with a uniform particle size was packed in a column and a flow-type adsorption capacity evaluation device (Kodansha Scientific published "Catalysis Experiment Handbook" (Catalyst Society))
(1986) Evaluation method described on page 44), and then test gas containing hydrogen sulfide with a concentration of 10 ppm (humidity 0%) was adjusted to 1 l / m.
The sample column was vented at a flow rate of in. The test gas that has passed through the sample column is sampled at regular intervals, and the hydrogen sulfide content concentration in the sampled test gas (column outlet) is shown in FIG.

From FIG. 1, it can be confirmed that the deodorant 1 (curve a in the figure) has a larger hydrogen sulfide adsorption capacity than the commercially available deodorant (curve b in the figure).

An electron micrograph (× 150,000) of the used bamboo leaf-shaped ferric oxide hydroxide powder is shown in FIG.

Example 2 A deodorant 1 and a commercially available deodorant (activated carbon (B)) as a comparative sample were respectively used as samples in the same manner as in Example 1 except that the test gas was changed to trimethylamine having a concentration of 10 ppm.
The measured value of the trimethylamine content concentration at the column outlet is shown in FIG.

From FIG. 2, it can be confirmed that the deodorant 1 (curve a'in the figure) has a larger adsorption capacity of trimethylamine than the commercially available deodorant (curve b'in the figure).

Example 3 Using the bamboo leaf-shaped ferric hydroxide-containing fine particles used in Example 1 and a needle-shaped ferric hydroxide-containing fine powder as a comparative product, the type of solid acid powder, the mixing ratio, and the test were conducted. Deodorizers 1 to 8 were prepared in the same manner as in Example 1 except that the gas humidity (0%, 80%) was changed variously, and the column outlet hydrogen sulfide after 120 minutes of aeration was prepared in the same manner as in Example 1. The values obtained by measuring the density are shown in Table 1.

The montmorillonite used was Montmorillonite 50.
g was added to 1 liter of 1N-HCl solution, immersed at 80 ° C. for 24 hours, washed with water and dried to obtain a solid acid.

The acicular hydrous ferric oxide fine particles used for comparison are
Long axis diameter 0.3 μm determined from electron micrograph, axial ratio (major axis diameter / minor axis diameter) 10, specific surface area 95 m ² / g determined by BET method
belongs to.

Example 4 The column outlet trimethylamine concentration after 120 minutes of aeration was measured in the same manner as in Example 3, except that the test gas was changed to trimethylamine having a concentration of 10 ppm using the deodorants 1 to 8 prepared in Example 3. The values obtained are shown in Table 1.

[Effects of the Invention] A deodorant composed of a mixed powder of ferric oxide-containing hydroxide powder and a solid acid powder according to the present invention is capable of removing sulfur-based malodorous substances and nitrogen-based malodorous substances in the air or gas from the influence of moisture. It is suitable as a deodorant because it efficiently adsorbs both without receiving it and does not pose a danger of handling, and has an excellent adsorbing ability especially when used at room temperature and dry type.

[Brief description of drawings]

FIG. 1 shows the evaluation results of the adsorption capacity of hydrogen sulfide gas of the deodorant obtained in Example 1. FIG. 2 shows the evaluation results of the adsorption capacity of the deodorant trimethylamine gas obtained in Example 2. FIG. 3 is an electron micrograph (× 150,000) showing the particle structure of the used bamboo leaf-shaped ferric oxide hydroxide fine powder.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kozo Iida 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Research Laboratory (72) Inventor Naoki Horiishi, 4 Fununairi Minami, Naka-ku, Hiroshima City, Hiroshima Prefecture Osamu Kawabata, Examiner, Creation Center, Toda Kogyo Co., Ltd.

Claims (1)

[Claims] 1. A major axis diameter of 0.1 which has a stripe-shaped ultrafine structure.
30 to 60% by weight of powdered ferric hydroxide particles having a bamboo leaf shape with an axial ratio (major axis diameter / minor axis diameter) of 3 to 10 at 2 to 1.0 μm and 40 to 70% by weight of solid acid powder Deodorant consisting of mixed powder.