JPH11137655A - Deodorant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To additionally improve deodorization performance by sufficiently extracting the intrinsic performance of a sticking agent. SOLUTION: This deodorant is composed by subjecting an adsorption carrier to an acid treatment and sticking the sticking agent consisting of at least either of a transition element and transition element component to the acid treated adsorption carrier after the acid treatment. Copper nitride is stuck to the carrier after the acid treatment, by which the sticking agent is stuck in the state of the copper nitrate and, therefore, the bivalent copper having a high effect as the sticking agent exists sufficiently and since the deodorization effect by a nitric acid radical is added, the deodorization performance is greatly improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorizing agent capable of effectively adsorbing and removing an odor-causing substance from air containing a trace amount of an odor-causing substance such as trimethylamine, methyl mercaptan, and hydrogen sulfide.

[0002]

2. Description of the Related Art There are various places in a living environment of a person, such as a toilet and a refrigerator, which generate a bad smell. This stench is
Trace amounts of various odor-causing substances, such as nitrogen-containing compounds such as ammonia and amines, and sulfur-containing compounds such as hydrogen sulfide and thiol, are contained in the air in trace amounts and are perceived by stimulating the odor. Therefore, conventionally, a deodorant has been used which adsorbs and removes an odor-causing substance in the air to produce air with no odor.

Activated carbon is widely used as such a deodorant. Activated carbon is porous and has a large specific surface area.
Therefore, the offensive odor-causing substance is adsorbed on the activated carbon surface and is thereby removed from the air, thereby reducing the offensive odor.
However, activated carbon has a selectivity for the type of odor causing substance to be adsorbed, and it is difficult to adsorb odor causing substances such as nitrogen-containing compounds. Therefore, Japanese Patent Application Laid-Open No. 2-180633,
JP-A-42744 and JP-A-8-281113 propose that activated carbon be impregnated with various additives to further enhance the deodorizing performance.

For example, Japanese Patent Application Laid-Open No. 8-281113 discloses a method in which a first additive comprising a transition element or a transition element compound and a second additive comprising a halogen or a halogen compound are supported on an adsorption carrier such as activated carbon or sepiolite. Deodorizers are disclosed. According to this deodorant, the first additive is excellent in the performance of removing sulfur-containing compounds, and the second additive oxidizes and decomposes the amine-based odor component into a substance that is easily adsorbed. Adsorbs and has excellent deodorizing performance.

[0005]

However, even in the case of activated carbon impregnated with an impregnating agent, the effect of the impregnating agent cannot be obtained as expected in an actual use environment in which a low-concentration odor-causing substance is present. However, there is a problem that the adsorption performance cannot be sufficiently exhibited. The present invention has been made in view of such circumstances, and an object of the present invention is to further improve the deodorizing performance by sufficiently drawing out the performance of an impregnating agent.

[0006]

According to a first aspect of the present invention, there is provided a deodorizing agent, wherein the adsorbent is subjected to an acid treatment, and the adsorbent after the acid treatment is treated with at least one of a transition element and a transition element compound. Or an impregnating agent consisting of

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A transition element or a transition element compound conventionally used as an impregnating agent has a high deodorizing performance against air containing a sulfur-containing compound as an odor-causing substance. The reason is considered to be that sulfide is generated by reacting with the sulfur-containing compound, and it is described in JP-A-8-281113 that copper or a copper compound exhibits a particularly high effect.

According to the study of the present inventors, for example, when copper or a copper compound is selected as the additive, divalent copper is effective for deodorization. On the other hand, adsorption carriers such as activated carbon have a large surface pH and are generally in an alkaline atmosphere. Therefore, for example, when copper nitrate (CuNO ₃ ) is used as the impregnating agent, after a part of the nitrate is replaced with a hydroxyl group, cupric hydroxide (Cu (OH) ₂ ) → cupric oxide (Cu
O) → cuprous oxide (Cu ₂ O), and it was presumed that divalent copper was reduced. As a result, it was considered that the deodorizing performance was not improved as expected.

Therefore, in the deodorant of the present invention, the adsorbent is first subjected to an acid treatment, and the adsorbent after the acid treatment is impregnated with an adduct comprising at least one of a transition element and a transition element compound. Since the state of the surface of the adsorption carrier changes due to the acid treatment, if, for example, copper nitrate is attached thereto,
It is impregnated in the form of copper nitrate without producing hydroxide. Therefore, it was clarified that, for example, divalent copper having a high effect as an impregnating agent was sufficiently present, and a deodorizing effect by nitrate was added, so that expected high deodorizing performance was obtained.

Further, since the transition element has remarkable performance as a Lewis acid, it forms a complex with a Lewis base having an unpaired electron. That is, the odor-causing substances having nitrogen atoms having unpaired electrons, such as amines and ammonia, are efficiently adsorbed. Therefore, the odor-causing substance can be selectively adsorbed from the atmosphere containing the odor-causing substance such as trimethylamine at a low concentration.

Examples of the adsorption carrier include activated carbon, hydrated magnesium silicate clay minerals, and combinations thereof. As the acid used for the acid treatment, an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, or an organic acid such as acetic acid can be used. The acid treatment is performed by bringing a solution of an acid selected from the above into contact with an adsorption carrier, followed by filtration, washing and drying. As a contact method, a method such as impregnation and spraying can be used,
It is also preferable to contact the acid solution in a boiling state in order to increase the reaction efficiency.

The acid strength of the acid solution used for the acid treatment may be larger than the acid strength of the adsorption carrier. If the acid strength is lower than the acid strength of the adsorption carrier, the effect of the acid treatment may not be obtained. As the acid solution, an aqueous solution, an alcohol solution, or the like is used. Further, it is desirable that the surface pH of the adsorption carrier after the acid treatment is 7 or less. If the surface pH is higher than this, sufficient properties of the impregnating agent may not be obtained, and the deodorizing performance may decrease.

As the transition elements, 3A to 7A in the periodic table of the elements,
Either group 8 or group 1B is used, but the fourth period element is preferable, and copper (Cu), iron (Fe), nickel (Ni), cobalt (Co), manganese (Mn) and the like are recommended. (Cu) is a particularly desirable element. Examples of the transition element compounds include nitrates, sulfates, chlorides, and acetates of these transition elements. In the case of copper, copper nitrate, copper sulfate, cupric chloride and the like are exemplified.

[0014] At least one of the transition element and the transition element compound to be attached to the adsorption carrier may be one of the above elements or compounds, or a plurality of them. The amount of the adhering is preferably in the range of 0.1 to 50 parts by weight based on 100 parts by weight of the adsorption carrier. If the amount is less than 0.1 part by weight, the effect of impregnation cannot be obtained and the deodorizing performance is reduced, and if the amount exceeds 50 parts by weight, the pores of the adsorbent are reduced and the original adsorbability of the adsorbent may be impaired. There is.

In order to produce the deodorant of the present invention, an acid solution is brought into contact with the adsorption carrier, and then an acid treatment of filtering, washing and drying is performed. Next, a solution containing at least one of a transition element and a transition element compound is brought into contact with the acid-treated adsorbent carrier, and the solvent is evaporated and dried to dryness, so that at least one of the transition element and the transition element compound is attached to the solution. be able to. Further, to contact the acid solution and a solution containing at least one of a transition element and a transition element compound with the adsorption carrier, a method of dispersing the adsorption carrier in the solution, a method of impregnating the adsorption carrier with the solution, or There is a method of spray-mixing the solution at the same time.

The deodorant of the present invention may be used as it is in the form of powder or granules, or may be used by attaching it to a filter or the like, and the form of use is not particularly limited.

[0017]

The present invention will be specifically described below with reference to examples and comparative examples. As shown in FIG. 1, the deodorizer of the present embodiment is composed of an acid-treated adsorption carrier 1 formed by acid-treating activated carbon, and cupric nitrate 2 attached to the acid-treated adsorption carrier 1. In powder form. The cupric nitrate 2 is impregnated at 20 parts by weight per 100 parts by weight of the acid-treated adsorption carrier 1. Hereinafter, a detailed description of the structure of the deodorant will be given by describing the production method.

(Example 1) First, 1 L of a hydrochloric acid aqueous solution having a concentration of 0.1 N (pH = 1 or less) was prepared, heated and boiled.
Activated carbon (20 g) was mixed therein, and the mixture was stirred in a boiling state for 1 hour. Thereafter, filtration, washing and drying were performed to prepare hydrochloric acid-treated activated carbon. The surface pH of the activated carbon treated with hydrochloric acid measured according to JISK1474 was 4.2.

Next, 0.77 g of cupric nitrate trihydrate was added to the beaker.
(0.6 g of anhydrous copper nitrate) was taken, water was added thereto to make about 50 ml, and the mixture was stirred and dissolved. 3 g of the above-mentioned activated carbon treated with hydrochloric acid was added to this aqueous solution, and water was evaporated while heating and stirring on a hot stirrer. When the water was almost evaporated, the whole beaker was transferred to a dryer at 105 ° C. and dried for 4 hours to obtain a deodorant of Example 1.

Example 2 First, 1 L of a hydrochloric acid aqueous solution having a concentration of 0.1 N (pH = 1 or less) was prepared, heated and brought to a boil.
Activated carbon (20 g) was mixed therein, and the mixture was stirred in a boiling state for 1 hour. Thereafter, filtration, washing and drying were performed to prepare hydrochloric acid-treated activated carbon. The surface pH of the activated carbon treated with hydrochloric acid measured according to JISK1474 was 4.2.

Next, 1 L of an aqueous solution of sulfuric acid having a concentration of 0.1 N (pH = 1 or less) was prepared, heated and boiled. 8.5 g of the activated carbon treated with hydrochloric acid obtained above was mixed therewith and stirred for 1 hour in a boiling state. Thereafter, filtration, washing and drying were performed to prepare activated carbon treated with sulfuric acid and hydrochloric acid. The surface pH of the activated carbon treated with sulfated hydrochloric acid measured according to JISK1474 was 3.6. Next, add 0.77 g of cupric nitrate trihydrate (as anhydrous copper nitrate)
0.6 g), water was added thereto to make about 50 ml, and the mixture was stirred and dissolved. 3 g of the activated carbon treated with sulfuric acid and hydrochloric acid
Was added and water was evaporated while heating and stirring on a hot stirrer. When the water was almost evaporated, the whole beaker was transferred to a dryer at 105 ° C. and dried for 4 hours to obtain a deodorant of Example 2.

Comparative Example 1 Cupric nitrate trihydrate was added to a beaker.
0.77 g (0.6 g of anhydrous copper nitrate) was taken, and water was added thereto to make about 50 ml, followed by stirring to dissolve. 3 g of activated carbon not treated with acid was added to this aqueous solution, and the water was evaporated while heating and stirring on a hot stirrer. When the water was almost evaporated, the whole beaker was transferred to a dryer at 105 ° C. and dried for 4 hours to obtain a deodorant of Comparative Example 1. In addition, JISK1474
The surface pH of activated carbon without acid treatment measured according to 9.9
Met.

Comparative Example 2 Activated carbon treated with hydrochloric acid was prepared in the same manner as in Example 1, and this was used as the deodorant of Comparative Example 2. (Comparative Example 3) Only activated carbon which was not acid-treated and did not have an impregnating agent was used as the deodorizing agent of Comparative Example 3.

(Testing / Evaluation)
mg and weigh each in a sample bag impermeable to gas. Each sample bag is attached to an adsorption test apparatus, and 5 liters of air containing hydrogen sulfide at a concentration of 100 ppm is introduced into the sample bag. Each sample bag containing air containing deodorant and hydrogen sulfide was allowed to stand in a constant temperature and humidity room maintained at 25 ° C for 24 hours, and the air in the sample bag before and after standing was analyzed by gas chromatography. And analyzed. Table 1 shows the conditions of the gas chromatograph.

[0025]

[Table 1] Then, the initial concentration (C _b ) of hydrogen sulfide before standing and the equilibrium concentration (C _s ) after standing for 24 hours are obtained, and the adsorption amount (q) of hydrogen sulfide adsorbed on the deodorant is calculated according to Equation 1. I asked.

[0026]

(Equation 1) Where: q: adsorption amount (mg / g) Mw: molecular weight of hydrogen sulfide V: sample bag capacity (ml) C _b : initial concentration (ppm) C _s : equilibrium concentration (ppm) t: test temperature (° C) W: Deodorant weight (g) Since hydrogen sulfide is also adsorbed to some extent on the sample bag itself, the same measurement is performed using only the sample bag without adding a deodorant, and the amount is subtracted from the adsorption amount (q). The corrected amount of adsorption was determined. From the corrected adsorption amounts, respective adsorption isotherms were created and extrapolated to obtain the adsorption amounts of hydrogen sulfide adsorbed on the respective deodorants when the hydrogen sulfide concentration became 40 ppm. Table 2 shows the results.

[0027]

[Table 2] From Table 2, it is clear that the amount of hydrogen sulfide adsorbed is significantly increased by the acid treatment and the impregnating agent, and the deodorizing performance is remarkably improved. Also, from the comparison between the comparative examples, the acid treatment alone did not increase the amount of hydrogen sulfide adsorbed, and the impregnation alone only slightly increased the amount of hydrogen sulfide adsorbed. It is considered that the effect of the impregnating agent is sufficiently drawn out.

[0028]

According to the deodorant of the present invention, since the effect of the impregnating agent is sufficiently exerted, the odor-causing substance can be efficiently adsorbed from air containing the odor-causing substance at a low concentration, and the deodorizing performance can be improved. It is extremely excellent.

Claims (1)

[Claims] 1. A deodorizing agent characterized in that an adsorbent is subjected to an acid treatment, and an adsorbent comprising at least one of a transition element and a transition element compound is attached to the adsorbent after the acid treatment.