JPH05317703A - Malodorous gas adsorptive agent - Google Patents

Abstract

PURPOSE:To obtain an agent with excellent deodorizing effect on aldehydes, especially acetaldehyde, high safety and easy handling by spreading at least one org. carboxylic acid and at least one org. amine on a porous substance and thereby forming a salt on the porous substance. CONSTITUTION:1-50 pts.org. amine and 1-50 pts.org. carboxylic acid are spread on 100 pts. porous substance and a salt is formed by scattering a water soln. of an org. acid on the porous substance. This air cleaning agent exhibits excellent adsorptive removing properties for aldehydes, especially acetaldehyde included in tabacco smoke, etc., which is one of the largest factor in malodorous ingredients in air. In addition, this cleaning agent exhibits not only high initial activity but less decrease in acetaldehyde adsorbability with time after spreading and can keep its effect for a long time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a malodorous gas adsorbent, and particularly to an adsorbent having excellent low malodorous gas adsorption. More specifically, it is an adsorbent that is excellent in adsorbing / removing aldehydes such as acetaldehyde contained in cigarette smoke, which is one of the largest causes of malodor in the air.

[0002]

2. Description of the Related Art In recent years, trace amounts of hydrogen sulfide, ammonia, mercaptan, which are present in living spaces due to changes in living environment,
There is increasing interest in malodorous gases such as amines and aldehydes. In order to remove these malodorous gases and maintain a comfortable living environment, a deodorant is required, and various malodorous gas adsorbents are also used in home life.

Since these malodorous gas adsorbents are used in daily life, they are required to satisfy the following conditions.

(1) It has an excellent deodorizing performance against various malodorous gases such as minute amounts of hydrogen sulfide, ammonia, mercaptans, amines and aldehydes existing in daily living space. (2) High safety.
(3) It should be easy to handle. (4) Be inexpensive.

Although there are many kinds of malodorous components contained in the air of general living spaces such as indoors or in cars, one of the most significant causes is aldehydes contained in cigarette smoke, especially acetaldehyde. Odor.

[0006] In general, activated carbon adsorbs malodorous substances in the gas phase at a relatively high equilibrium adsorption amount even at a low concentration, and thus is advantageous as compared with other deodorants and is widely used at present. However, the adsorption of aliphatic aldehydes such as formaldehyde and acetaldehyde from the low-concentration gas phase is poor.
If m, the acetaldehyde equilibrium adsorption amount of activated carbon is 0.1%.
Therefore, even at 100 ppm, it reaches only 0.65%.

As an attempt to improve this drawback, a method of impregnating an activated carbon with an ammonium salt, a sulfite, or an acidic sulfite has been proposed (JP-A-53-29292). However, the effect is not sufficiently satisfactory, and the effect is remarkably low especially in the low concentration region which is a problem in the case of removing malodor in the living space.

Further, activated carbon impregnated with aniline as an adsorbent mainly for removing acetaldehyde in the air is disclosed in JP-B-60-54095, JP-A-252043 and JP-A-3-98642. ing. Currently, activated carbon impregnated with aniline is widely used as an air purifying agent inside or inside a vehicle. However, it is needless to say that aniline is originally a poisonous substance and it is not preferable to use it for deodorization in ordinary households.

Other organic deodorants are also available, but they have low heat resistance, are difficult to process, and are expensive. Further, a deodorant obtained by adding ascorbic acid to iron sulfate is also used. A deodorant having such a composition has a good deodorizing effect on basic malodorous gases such as ammonia and amine, but has almost no deodorizing effect on hydrogen sulfide, mercaptan, aldehyde, etc., and dissolves when wet with water. However, it has a drawback that it cannot be used for deodorizing wet gas.

Many other chemical deodorants have been disclosed, but many have strong acidity and alkalinity, and the types of gases that can be removed are limited, which has the drawback that they are easily affected by moisture absorption or drying. There are many things.

A deodorant obtained by impregnating an inorganic polybasic acid on bentonite (JP-A-60-43373), a catalyst based on vitamin B12 (JP-A-61-164556), and a metal phthalocyanine (JP-A-61-164556). 62-131514) and the like are also disclosed, but the adsorption performance is poor and the effect is small.

[0012]

DISCLOSURE OF THE INVENTION The present invention is intended to remove a trace amount of malodorous components existing in daily living space, and has an excellent deodorizing effect against malodorous gas such as aldehyde which is a particular problem. And is safe and easy to handle,
It is intended to provide a malodorous gas adsorbent having a new composition.

[0013]

Means for Solving the Problems The present inventors have conducted various studies in search of a new adsorbent having excellent adsorbability and capable of sufficiently exerting the effect particularly in a low concentration region.
The adsorbent obtained by impregnating a salt of an organic acid with a porous material such as activated carbon has an extremely high ability to remove aliphatic aldehydes (particularly lower aliphatic aldehydes) such as formaldehyde and acetaldehyde in the gas phase. I found it. Based on this, the composition of the adsorbent and the carrier supporting it were examined, and the present invention was reached.

That is, it is a malodorous gas adsorbent obtained by impregnating a porous material with at least one organic carboxylic acid and at least one organic amine to form a salt on the porous material. It is more preferable that the porous substance is activated carbon.

The term "on a porous material" as used herein means that many porous materials often consist of micropores or cracks, but not only the surface of these materials that can be observed from the outside but also the internal micropores or cracks. It is meant to include. The present invention will be described in detail below.

A feature of the present invention is that an adsorbent is obtained by impregnating a porous substance such as activated carbon with a salt of organic amine-organic acid as described above. In addition to salts formed from organic amine-organic acid, for example, when only organic amines such as aniline, ethylenediamine, triethylenetetramine, etc. are impregnated as amine, the porous material also has good adsorption performance for aliphatic aldehydes. Have. However, even if the amount of these amines impregnated is suppressed to the extent that the adsorption performance is not lost, the porous substance impregnated with these amines has a strong amine odor and is not suitable for practical use as an adsorbent. there were. On the other hand, when an organic amine-organic acid salt is used, even if it is attached to a porous material to the extent that it exhibits sufficient adsorption performance, it does not feel the odor of amine and is suitable as an adsorbent. Was recognized.

The deodorant of the present invention requires the use of a porous material as a carrier for the organic amine-organic acid salt. Here, as the porous body, for example, activated carbon, activated alumina, silica gel, zeolite or the like can be used.

The activated carbon used as the carrier here generally has a large surface area of several 100 m ² or more per 1 g, and can be widely used as long as it is a carbon material exhibiting a high adsorptivity. As the raw material for the activated carbon, a charcoal such as coconut shell or wood is usually used, or coal is used. Further, the activation method may be obtained by any method such as a method of activating with steam or carbon dioxide at a high temperature or a method of treating with a chemical such as zinc chloride, phosphoric acid or concentrated sulfuric acid.

Although the shape of crushed coal, granulated coal or granulated coal is effective, a sheet-shaped adsorption layer impregnated with granulated coal or activated carbon is convenient for handling such as pressure loss and replacement. Granulated charcoal is 30 to 60 per 100 parts of carbon material according to the conventional method.
It is adjusted by adding a part of petroleum pitch or coal tar as a binder and activating after mixing and molding.

As the porous material other than activated carbon, zeolite, alumina, silica gel, pumice stone, urethane foam
It can be used in a wide range as long as it is porous, such as rubber, fiber, paper and cloth.

The shape of these porous substances is not particularly limited, but, for example, in addition to granular and powdery forms, fibrous, honeycomb, sheet-like, cloth-like, felt-like or powdery porous substances can be used. It is possible to use one attached to a urethane foam or the like, or one having a honeycomb structure formed by corrugating a paper coated with a powdery porous material.

As the organic acid, a monobasic acid such as formic acid, acetic acid and propionic acid, a dibasic acid such as oxalic acid, malonic acid and succinic acid, as well as a polybasic acid having at least a tribasic acid can be used.

As the organic amine compound, in addition to methylamine, ethylamine, ethanolamine, triethanolamine, aniline, propylamine and the like, polybasic amines such as ethylenediamine, triethylenetetramine and polyethyleneimine can be used.

The amount of the organic acid and the organic amine to be added to the porous substance is 1.0 to 50.0% by weight, preferably
It is 3 to 30% by weight. This is because if the impregnated amount is less than 1.0% by weight, the effect of impregnating the organic acid and the organic amine is poor, and if the impregnated amount exceeds 50.0% by weight, the adsorptivity of the porous substance is impaired.

The ratio of amine to acid for forming a salt is 0.8 to 1.5, preferably 1.1 to 1.3, in terms of equivalent ratio of organic acid / organic amine. The equivalent ratio of organic acid / organic amine is
When it is 0.8 or less, the bond of the generated ion complex becomes weak and the organic amine is easily desorbed, which is not preferable.

In order to adjust the deodorant of the present invention, it is preferable to preliminarily impregnate the porous substance with a predetermined amount of the amine and then impregnate a predetermined amount of the acid. Specifically, it is obtained by adsorbing an organic amine on a porous body by an adsorption method or a sprinkling method, then sprinkling an aqueous solution of an organic acid to impregnate a predetermined amount thereof, and drying this at 100 ° C. or higher.

Alternatively, it can also be obtained by adding an aqueous solution of an acid to an aqueous solution of an organic amine to form a salt, sprinkling the aqueous solution of the organic amine-organic acid salt on a porous body, and drying and attaching the salt.

The porous substance attached by any of the methods also exhibits sufficient adsorption performance for acetaldehyde and the like.

[0029]

[Function] A porous substance impregnated with an organic acid and an organic amine not only shows a smaller decrease in acetaldehyde adsorbability over time after impregnation as compared with a porous substance impregnated with the same amount of amine only, but also Acetaldehyde adsorption is also high. That is, it has excellent properties as an air purifier with little deterioration in acetaldehyde adsorption performance and high initial activity.

Further, even when this air purifying agent was heated to 150 ° C., no decomposition of amines was observed, and no deterioration in aldehyde adsorption performance was observed. It is considered that this action is due to the fact that the organic acid stabilizes the amine, but the details of the mechanism are not clear.

In the room of a living space such as an office or home, the odor of tobacco is usually felt strongly, but in terms of composition, in addition to acetaldehyde, ammonia, lower amines, hydrocarbons,
Contains hydrogen sulfide, etc. Among these components, the cleaning agent of the present invention is extremely excellent in the adsorbability of acetaldehyde, which is the main component of the odor of tobacco, but the adsorbability of the other components is not always sufficient. Therefore, although the air purifying agent of the present invention can be used alone, it is more effective when used in combination with another purifying agent.

[0032]

EXAMPLES The present invention will be described more specifically with reference to the following examples.

(Examples 1 to 12 and Comparative Examples 1 to 6) As the porous substance, activated carbon prepared by using a charcoal of coconut shell as a raw material, crushed carbon having a particle size of 6 to 10 mesh and powder thereof are coal tar pitch. Using as a binder, granulated charcoal molded into a diameter of 2 mm and a length of several mm was used. Neobead C manufactured by Mizusawa Chemical Co., Ltd. was used as the alumina, and Carriact 50 manufactured by Fuji Gel Co., Ltd. was used as the silica gel. A sample was prepared by sprinkling an amine and an acid onto the porous material under the following preparation conditions to attach the porous material and then drying.

Example 1: 100 parts of crushed coal, 10 parts of diethylenetriamine, 12 parts of oxalic acid

Example 2: 100 parts of granulated coal, 10 parts of triethylenetetramine, 10 parts of maleic acid

Example 3: 100 parts of crushed coal, 10 anilines
Part, maleic acid 10 parts

Example 4: 100 parts of granulated coal, 30 parts of polyethyleneimine, 15 parts of oxalic acid

Comparative Example 1: 100 parts of crushed coal, 10 parts of diethylenetriamine

Comparative Example 2: 100 parts of granulated coal, 10 parts of triethylenetetramine

Comparative Example 3: 100 parts of crushed coal, aniline
10 copies

Comparative Example 4: 100 parts of granulated coal, 30 parts of polyethyleneimine

Example 5: 100 parts of crushed coal, ethylamine
15 parts, succinic acid 25 parts

Example 6: 100 parts of granulated coal, 10 parts of ethanolamine, 15 parts of fumaric acid

Comparative Example 5: 100 parts of crushed coal, ethylamine
15 copies

Comparative Example 6: 100 parts of granulated coal, 10 parts of ethanolamine

Example 7: 100 parts of alumina, 10 parts of triethylenetetramine, 10 parts of maleic acid

Example 8: 100 parts alumina, 20 parts triethylenetetramine, 20 parts maleic acid

Example 9: 100 parts alumina, 30 parts triethylenetetramine, 30 parts maleic acid

Example 10: 100 parts alumina, 40 parts triethylenetetramine, 40 parts maleic acid

Example 11: 100 parts silica gel, 15 parts diethylenetriamine, 15 parts oxalic acid

Example 12: 100 parts silica gel, 30 parts diethylenetriamine, 30 parts oxalic acid

Next, in a glass bottle with a capacity of 3.97 l, 2 g of water was added.
The sample is put in, degassed for a while with a vacuum pump, and then a predetermined acetaldehyde solution is added to vaporize. Next, after introducing air to return to normal pressure, leave it in a constant temperature bath at 25 ° C. After 24 hours, the acetaldehyde concentration was measured with a gas detector tube. The relationship between the adsorbed amount of acetaldehyde and the concentration when equilibrium was reached was examined, the isotherm at 20 ° C was measured, and the adsorbed amount at a gas concentration of 10 ppm was calculated.

[0053]

[Table 1]

A sample was placed in a plastic bag, sealed, and stored at 60 ° C. for 1 month. Then, the sample was tested and the amount of adsorption was measured.

The measurement results are shown in Table 2.

[0056]

[Table 2]

As a result, the porous body having the organic amine-organic acid ion complex impregnated not only has a higher initial amount of acetaldehyde adsorbed but also has a lower adsorption amount over time as compared with the porous body having only the amine impregnated therein. It turns out to be small.

Next, the desorption property of the attached amines was examined. A 100 mm sample was packed into a 50 mmΦ glass tube column set in a constant temperature bath at a temperature of 100 ° C, fresh air at a temperature of 50 ° C was passed at a flow rate of 470 ml / min, and the gas concentration of amines in the outlet gas was measured with a gas detection tube. It was measured.

The results are shown in FIG.

[0060]

EFFECT OF THE INVENTION The air purifying agent of the present invention is excellent in adsorbing / removing aldehydes, especially acetaldehyde, contained in cigarette smoke, which is one of the largest factors among malodorous components in the air. ing. Further, the purifying agent has a characteristic that not only the initial activity is high, but also the acetaldehyde adsorbing ability does not decrease with the lapse of time after the impregnation, and the effect can be maintained for a long time.

[Brief description of drawings]

FIG. 1 shows the relationship between aeration time and amine concentration in aeration gas.

[Explanation of symbols]

 1 Example 1 2 Example 2 3 Example 3 4 Example 4 5 Comparative Example 1 6 Comparative Example 2 7 Comparative Example 3 8 Comparative Example 4

Claims (3)

[Claims] 1. A malodorous gas adsorbent obtained by impregnating a porous material with at least one organic carboxylic acid and at least one organic amine to form a salt on the porous material. 2. Organic amine 1 to 50 per 100 parts of porous material
Part and 1 to 50 parts of organic carboxylic acid are impregnated to form a salt on the porous material, and the malodorous gas adsorbent according to claim 1. 3. The malodorous gas adsorbent according to claim 1, wherein the porous substance is activated carbon.