JPH08206185A - Deodorant - Google Patents

Abstract

PURPOSE: To provide a deodorant which is easy to handle and compact with a limited pressure loss when incorporated into a deodorizing processor. CONSTITUTION: An aqueous solution containing polyvinyl alcohol, manganese and copper nitrates and a surfactant are added to silica particles to make a slurry. The slurry is applied on the skeleton of a urethane foam to be absorbed, dried and baked. An aqueous solution containing manganese and copper nitrates is applied on a structural body obtained to be absorbed, dried and baked. Thereafter, the operation of applying the above aqueous solutions, absorption, drying and baking are repeated to obtain the structural body, thereby malodorous gas can effectively be removed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a deodorant, and more particularly to a deodorant containing a three-dimensional open cell structure containing manganese oxide and / or copper oxide.

[0002]

2. Description of the Related Art Deodorants containing manganese oxide and / or copper oxide as active ingredients have been known. For example, 40% by weight of manganese dioxide, 20% by weight of copper oxide and 40% by weight of γ-alumina are mixed and compression-molded into a tablet-like deodorizing agent (Japanese Patent Laid-Open No. 50-30795).
JP-A No. 1-151938) and the like, and deodorizing agents containing manganese and copper oxides in A-type zeolite.

[0003]

However, Japanese Patent Laid-Open No. Sho 50-
The deodorant disclosed in Japanese Patent No. 30795 has a drawback that when it is incorporated into a deodorizing apparatus, the pressure loss during gas passage becomes large, and the deodorant disclosed in JP-A-1-151938 is Since it is in the form of granules or powder, it has the drawbacks that it is easily scattered and pollutes the environment and is difficult to handle.

An object of the present invention is to provide a deodorant containing manganese oxide and / or copper oxide as an active ingredient, which is easy to handle, is compact, and has a small pressure loss when incorporated in a deodorizing apparatus. Is to provide.

[0005]

DISCLOSURE OF THE INVENTION As a result of various studies on deodorizing agents for effectively removing malodorous gas in the air, the present inventors have found that manganese oxide and / or copper oxide have an appropriate strength. The present invention has been completed by finding that it becomes a deodorant that is easy to handle when baked into a three-dimensional open cell structure.

That is, the present invention relates to manganese oxide and / or
Alternatively, the present invention relates to a deodorant containing a copper oxide-containing three-dimensional open cell structure.

The three-dimensional open cell structure in the present invention is a solid (that is, a cell structure) formed by a network of dense solid pillars or flat plates forming the edges and faces of the cell, which are connected to each other. It is a structure that has a space that is connected to, and is also called an open-cell structure. In addition to the open cell structure, the cell structure also includes a closed cell structure (also called a closed cell structure) and an intermediate cell structure in which both the open cell structure and the closed cell structure coexist. However, the “open cell structure” in the present invention includes not only an open cell structure but also the above intermediate cell structure.

The porosity of the three-dimensional open cell structure used in the present invention, the size of the bubbles and the thickness of the skeleton are not particularly limited, but the porosity is usually 50 to 97%, preferably 80. ~ 90%, bubble size is usually 0.5-10
mm, preferably 1-5 mm, skeleton thickness is usually 0.1
It is about 2.0 mm, preferably 0.2 to 1.0 mm.

The manganese oxide contained in the three-dimensional open cell structure used in the present invention includes MnO ₂ and MnO and Mn.
Various oxidation forms such as n ₃ O ₄ , Mn ₂ O ₃ and Mn ₂ O ₇ can be adopted, but the form of MnO ₂ is most preferable. Further, the copper oxide contained in the cell structure having the three-dimensional communication space used in the present invention can take an oxidized form such as Cu ₂ O and Cu ₄ O in addition to CuO, but the form of CuO is most preferable. . When both manganese oxide and copper oxide coexist, the existence of the form of Mn-Cu composite oxide is also presumed.

When the amounts of manganese oxide and copper oxide in the cell structure are changed, the deodorizing efficiency also changes. Since the deodorization efficiency varies depending on the type of malodorous gas, the optimum ratio may be appropriately examined and determined according to the type. When the malodorous gas is methyl mercaptan, the ratio of manganese oxide to copper oxide is about 4: 1 in terms of element weight ratio, or 2:
Deodorization efficiency is highest around 3.

The cell structure containing manganese oxide and / or copper oxide is generally highly effective in removing sulfur malodorous gas. In addition to manganese oxides and / or copper oxides, magnesium, titanium, silicon, aluminum, iron,
It is also possible to include an oxide of a metal such as zinc.

The three-dimensional open cell structure containing manganese oxide and / or copper oxide can be manufactured by the following method. Method: (a) Fine particles of silica, alumina, cordierite, magnesia, etc. in the skeleton of a resin having a three-dimensional open cell structure such as urethane foam; water-soluble metal salts of manganese and / or copper; and polyvinyl alcohol, etc. The water-soluble organic binder containing the above water-soluble organic binder is deposited and absorbed, and the excess slurry is removed, and (b) dried, (c) fired, and (d) the obtained fired product contains manganese and / or copper. Adsorption and absorption of the contained salt aqueous solution, (e) drying, (f)
Baking, and (g) repeating the operations (d) to (f) described above.

The three-dimensional open cell structure containing manganese oxide and / or copper oxide can also be manufactured by another method as follows. Alternative method: A commercially available open-cell structure ceramic filter is coated with a salt solution containing manganese and / or copper.
It is absorbed, dried and calcined to form manganese and / or copper oxides on the ceramic filter.

The deodorizing agent containing manganese and / or copper as an active ingredient is particularly effective for removing sulfur-based malodorous gas. This is because the structure containing manganese and / or copper catalyzes a reaction for converting a malodorous gas such as hydrogen sulfide or methyl mercaptan into a substance having a low threshold value as shown in the following reaction formula. Therefore, the deodorant of the present invention is characterized by having a longer life than an adsorption type deodorant such as activated carbon. H ₂ S → S (1) CH ₃ SH → CH ₃ S-SCH ₃ (2)

[0015]

EXAMPLES The present invention will be described in more detail with reference to experimental examples and examples. Experimental Example Proportion of manganese dioxide and copper oxide and deodorization ratio Manganese dioxide and cupric oxide were weighed so that the weight ratio of manganese: copper to the element ratio was 1: 1, and the two were mixed. The powder was crushed and mixed with a ball mill manufactured by K.K. Separately, the weight ratio of manganese: copper is 5: 0 (manganese dioxide alone), 4: 1, 3: 2,
Manganese dioxide and cupric oxide were weighed so as to be 2: 3, 1: 4, and 0: 5 (copper oxide alone), and treated in the same manner as above to obtain a test powder.

Prepare 1 L of polypropylene closed beaker 2 (pieces) × 6 (type of test powder), 10 μL of 25% sodium methyl mercaptan aqueous solution for each
Take the (odor source) and put 2g of test powder in one beaker.
The test powder was not added to the other beaker, and the beaker was allowed to stand at room temperature for 30 minutes, the methylmercaptan concentration after the stand was measured, and both were compared. The methyl mercaptan concentration was measured with a detector tube (Fig. 1). The horizontal axis of FIG. 1 is the element weight ratio of manganese to copper in the powder, and the vertical axis is the removal rate = (Cs−Co) / Co ×
It is 100 (%). Here, Co represents the concentration (ppm) when the test powder was not added, and Cs represents the concentration (ppm) when the test powder was added. It can be seen from FIG. 1 that methyl mercaptan, which is a malodor source, is effectively removed when the ratio of manganese to copper is around Mn: Cu = 4: 1 or around 2: 3.

Example 1 Production of three-dimensional open cell structure containing manganese oxide and copper oxide and deodorizing effect 1.0 g of silica particles (manufactured by Nippon Aerosil) was weighed, and 3 wt% polyvinyl alcohol and 64 wt% nitric acid were added to the weighed silica particles. A slurry was prepared by adding 10 g of an aqueous solution containing manganese and 12 wt% copper nitrate, and stirring the mixture while adding a small amount of a surfactant Pluronic L-61 (manufactured by Asahi Denka Co., Ltd.). 20 mm in this slurry
Urethane foam (Everlite SF HR-13 manufactured by Bridgestone Co., Ltd.) having a size of 40 mm and 50 mm was dipped, taken out, and excess slurry was lightly squeezed out. This is heated at 120 ° C for 1 hour, dried, and then transferred to a muffle furnace, where it is heated from 200 ° C to 10 ° C.
The temperature was raised to 00 ° C. over about 4 hours to remove the base (urethane foam) and perform firing (the structure obtained at this point is still brittle). After cooling, the resulting structure is 64 wt.
% Manganese nitrate and 12 wt% copper nitrate-containing aqueous solution, take this out, heat at 120 ° C. for 1 hour, dry,
Baking was performed at 450 ° C. for 30 minutes in a muffle furnace. afterwards,
Immersion in the aqueous salt solution containing manganese and copper, followed by drying and firing was repeated three more times to obtain a strong cell structure. The compressive strength of the obtained structure was measured using a Tensilon (RTM-100, manufactured by Orientec Co., Ltd.) at a compression speed of 10 mm / min, and it was 37 gf / cm ² with respect to the apparent area.

This cell structure has a performance as a deodorant. When this cell structure was hung in a closed 1 L beaker containing 300 ppm of methyl mercaptan and allowed to stand, the concentration could be reduced to 60 ppm after 20 minutes.

Example 2 Production of three-dimensional open cell structure containing manganese oxide and copper oxide supported on ceramic foam An aqueous solution containing 32 wt% manganese nitrate, 6 wt% copper nitrate and 27 wt% magnesium nitrate was prepared. 15 mm x 3
It was impregnated with 0 mm × 40 mm ceramic foam (# 13 manufactured by Bridgestone Corp.) and dried at 100 ° C. afterwards,
The aqueous solution containing copper nitrate and magnesium nitrate was again impregnated, dried at 100 ° C., and impregnated and dried three times, and then calcined at 450 ° C. for 3 hours in a muffle furnace to obtain a cell structure. Obtained.

[0020]

According to the present invention, it is possible to provide a deodorant that is easy to handle, compact, and has a small pressure loss when incorporated in a deodorizing apparatus.

[Brief description of drawings]

FIG. 1 is a graph showing the influence of the ratio of manganese dioxide / copper oxide on the methyl mercaptan removal rate (average value and standard deviation of three measurements).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B01J 23/34 A 23/72 A 23/889

Claims (1)

[Claims] 1. A deodorant comprising a three-dimensional open cell structure containing manganese oxide and / or copper oxide.