JPH07171384A - Adsorbent for offensive odor - Google Patents

Abstract

PURPOSE:To obtain an adsorbent which has a good deodorant effect on gases with offensive odor including aldehyde and is easy in handling by loading metal acetate on a porous material to adsorb the gases. CONSTITUTION:Metal acetate of iron, chromium, nickel or the like is loaded on a porous material such as active carbon. The amount of the loaded metal acetate is 0.5-30 pts.wt. per 100 pts.wt. of the porous material. The adsorbent thus obtained, which has a function of catalytic decomposition, is effective to adsorb aliphatic aldehyde, low molecular weight aliphatic aldehyde in particular, such as formaldehyde and actaldehyde in a gas phase. Therefore, aldehydes contained in cigarette smoke, etc., which cause offensive odor existent in daily life, can be removed effectively with the adsorbent.

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. More specifically, it relates to acetaldehyde and other aldehydes contained in cigarette smoke, which is one of the major causes of malodor in the air. It is an adsorbent that is excellent in adsorption / removability, and has the characteristic of adsorbing malodorous gas of low concentration.

[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 everyday 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) It should be inexpensive.

There are many kinds of malodorous components contained in the air of ordinary living spaces such as indoors or in vehicles, but one of the most significant causes is mainly 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 therefore has superior properties as compared with other deodorants and is currently most widely used. . However, when a trace amount of an aliphatic aldehyde such as formaldehyde or acetaldehyde is contained in the gas phase, the adsorptivity is low.For example, even if coconut shell activated carbon with excellent adsorption performance in the gas phase is used, the results of the adsorption test When the acetaldehyde concentration in the gas phase is 26 ppm, the acetaldehyde equilibrium adsorption amount of activated carbon is 0.1%, and even at 100 ppm.
Only reaches 0.65%.

As an attempt to improve this drawback, a method of impregnating an activated carbon with an ammonium salt, a sulfite salt, or an acidic sulfite salt 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, which is mainly used as an adsorbent for removing acetaldehyde in 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 goes without saying 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. In addition, 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 and aldehyde, and dissolves when wet with water. Therefore, 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 or alkalinity, and the types of gas 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 by vitamin B12 (JP-A-61-164556), and a metal phthalocyanine (JP-A-61-164556). 62-131514), etc., but the adsorption performance is poor and the effect is small.

[0012]

DISCLOSURE OF THE INVENTION The present invention is intended to remove a small amount of malodorous components present in daily living space, and has an excellent deodorizing effect on malodorous gases such as aldehyde which are particularly problematic. 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 which has excellent adsorptivity and can exhibit high adsorptivity especially in a low concentration region. As a result, iron, chromium, nickel, An adsorbent obtained by impregnating an acetic acid salt of one or more metals such as cobalt, manganese, copper, magnesium, zinc, and calcium with a porous body such as activated carbon has a catalytic decomposition action and has a gas phase. It was found that the adsorbability of aliphatic aldehydes such as formaldehyde and acetaldehyde, especially lower aliphatic aldehydes, is extremely high. Based on this, the composition of the adsorbent and the carrier supporting it were examined, and as a result, the present invention was reached.

That is, it is a malodorous gas adsorbent obtained by impregnating at least one metal acetate with a porous substance.
It is more preferable that the porous substance is activated carbon.
Furthermore, the amount of metal acetate impregnated was 0.
More preferably, it is from 5 to 30 parts.

The term "porous substance" as used herein usually means that the surface of the porous substance is usually composed of micropores or cracks, but not only the surface of these substances that can be observed from the outside but also the inside micropores or cracks. It is meant to include. The present invention will be described in detail below.

The deodorant of the present invention requires the use of a porous substance as a carrier for metal acetate. As a porous body, it does not deteriorate the metal acetate and can be widely used as long as it is a material having a large specific surface area and high adsorptivity as described above.
There is no particular limitation. For example, activated carbon, zeolite, activated alumina, silica gel and the like.

The activated carbon used as the carrier here generally has a large specific 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 of the activated carbon, a charcoal such as coconut shell or wood or coal is usually used, but any may be used. The activation method is also a method of activating at high temperature with steam or carbon dioxide,
Alternatively, it may be obtained by any method such as a method of treating with a chemical agent such as zinc chloride, phosphoric acid or concentrated sulfuric acid.

The shape of the activated carbon can be any of crushed coal, granulated coal and granulated coal, but a sheet-shaped adsorption layer impregnated with the granulated carbon or activated carbon is convenient in terms of handling such as pressure loss and replacement. Granulated coal is added to 100 parts of carbon material according to the conventional method.
It is prepared by adding 60 parts of petroleum pitch or coal tar as a binder, mixing and molding, and then activating.

The zeolite used in the present invention is an aluminosilicate, which is a substance having a three-dimensional skeleton and a pore structure formed in the gaps. It has a large specific surface area of more than 500 m ² / g and high adsorptivity based on it. Its composition,
The structure is not particularly limited, and both natural products and synthetic products can be used. Further, the pore volume, particle size, and shape are not particularly limited, but the pore volume depends on the adsorption amount of metal acetate and the pressure loss.
At 0.3ml / g or more, the particle size is 50 mesh or less (particle size is about 0.3mm
Or more) is preferable.

The activated alumina used in the present invention is mainly composed of alumina oxide, has a porous structure, and exhibits a high adsorptivity. The pore volume, particle size and shape are not particularly limited, but the pore volume depends on the metal acetate impregnation capacity and pressure loss.
At 0.3ml / g or more, the particle size is 50 mesh or less (particle size is about 0.3mm
Or more) is preferable.

The silica gel used in the present invention is an adsorbent produced by solidifying a silicic acid colloidal solution. The main component is silicon dioxide, which has a pore structure, has a surface area of 90 to 500 m ² / g, and exhibits high adsorption. The pore volume, particle size, and shape are not particularly limited, but the pore volume is 0.3 ml / g or more and the particle size is 50 due to the relationship between the adsorption amount of metal acetate and the pressure loss.
A mesh or less (particle diameter of about 0.3 mm or more) is preferable.

Among these porous materials, activated carbon has a large specific surface area and thus a large metal acetate carrying capacity, and since the surface is non-polar, there is no possibility of reacting with acetate and causing a chemical change. It is most preferable as a carrier for metal acetate, since it has a high adsorbability of a malodorous substance in the phase and thus has a high rate of deodorizing a malodorous substance, and that the deodorizing rate does not decrease even after long-term use.

The shape of these porous materials is not particularly limited. For example, in addition to granular or powdery shapes, fibrous, honeycomb, sheet-like, cloth-like, felt-like, or powdery porous materials may be used as urethane foam. And the like, or a corrugated paper coated with a powdery porous material to form a honeycomb structure can be used.

The metal contained in the acetate is not particularly limited, but is preferably one or more of iron, chromium, nickel, cobalt, manganese, copper, magnesium, zinc and calcium.

The feature of the present invention resides in that a porous substance such as activated carbon having a metal acetate salt impregnated therein is used as an adsorbent. Even if a metal salt other than acetate is impregnated, good adsorption performance for aliphatic aldehydes cannot be obtained. However, even if it is a metal salt other than acetate, one that can easily form a metal acetate in the presence of acetic acid, for example, metal carbonate, hydroxide, etc. Acts as an adsorbent of the invention.

In order to prepare the deodorant of the present invention, it is preferable that a metal salt is previously impregnated into the porous substance in a predetermined amount and then a predetermined amount of acetic acid is impregnated therein. Specifically, hydroxide,
It is obtained by adsorbing an aqueous salt solution of chloride, carbonate or the like on the porous body by an adsorption method or a sprinkling method, then impregnating a predetermined amount of an aqueous solution of acetic acid by the sprinkling method, and drying this at 100 ° C. or higher.

Alternatively, it can also be obtained by adding acetic acid to an aqueous solution of a metal acetate, sprinkling the aqueous solution on a porous material, drying and impregnating it.

The porous substance attached by either method shows sufficient catalytic decomposition performance for acetaldehyde and the like.

The amount of metallic acetic acid impregnated with respect to the porous material is not particularly limited, but is preferably 0.1 to 20.0% by weight, and 2 to 10%.
Weight percent is more preferred. When the impregnated amount is less than 0.1% by weight, the catalytic action tends to be slightly lowered, and when the impregnated amount exceeds 20.0% by weight, the adsorptivity of the porous substance is hindered, and the deodorizing property tends to decrease. This is because.

[0030]

The porous substance to which the metal acetate is impregnated has less deterioration in the acetaldehyde catalytic decomposition performance with the passage of time after the impregnation. That is, it has excellent properties as an air purifying agent, with little deterioration in acetaldehyde catalytic decomposition performance and high initial activity.

Further, even when this air purifying agent was heated to 150 ° C., no decomposition of metal acetates was observed, and no degradation of aldehyde catalytic decomposition performance was observed.

It is considered that this action is due to the fact that the surface of the porous substance stabilizes the metal acetate, but the details of the mechanism are not clear.

The odor of cigarettes is usually strongly felt in the interior of living spaces such as offices and homes, but in terms of composition, in addition to acetaldehyde, ammonia, lower amines, hydrocarbons,
Contains hydrogen sulfide, etc. Among these components, the purifying agent of the present invention is extremely excellent in adsorbing acetaldehyde, which is the main component of tobacco odor, but is not necessarily sufficient in adsorbing other components. 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.

[0034]

EXAMPLES The present invention will be described in more detail with reference to the following examples. (Examples 1 to 12, Comparative Examples 1 to 6) As the porous substance,
Activated carbon prepared from coconut shell charcoal as a raw material,
Crushed coal having a particle size of 6 to 10 mesh and granulated coal obtained by molding the powder thereof with coal tar pitch as a binder to a diameter of 2 mm and a length of several mm were used. As alumina, Mizusawa Chemical Co., Ltd.
"Neobead C" manufactured by Fuji Gel as silica gel
"Carriact 50" manufactured by Co., Ltd. was used. A sample was prepared by sprinkling and adhering a metal acetate on a carrier according to the following preparation conditions and then drying.

Example 1 100 parts crushed coal 2 parts manganese acetate Example 2 100 parts granulated coal 5 parts manganese acetate Example 3 100 parts crushed coal 1 part cobalt acetate Example 4 100 parts granulated coal 3 parts cobalt acetate

Comparative Example 1 100 parts of crushed coal 2 parts of acetic acid Comparative example 2 100 parts of granulated coal 3 parts of acetic acid Comparative example 3 100 parts of crushed coal 2 parts of manganese hydroxide Comparative example 4 100 parts of granulated coal 3 parts of cobalt hydroxide

Example 5 Crushed coal 100 parts Chromium acetate 1 part Example 6 Granulated coal 100 parts Nickel acetate 2 parts

Comparative Example 5 Crushed coal 100 parts Chromium carbonate 1 part Comparative Example 6 Granulated coal 100 parts Nickel formate 2 parts

Example 7 Alumina 100 parts Manganese acetate 2 parts Example 8 Alumina 100 parts Cobalt acetate 2 parts Example 9 Alumina 100 parts Chromium acetate 2 parts Example 10 Silica gel 100 parts Iron acetate 10 parts Example 11 Silica gel 100 parts Acetic acid Nickel 5 parts Example 12 Silica gel 100 parts Zinc acetate 10 parts

Next, in a glass bottle having a capacity of 3.97 l, 2 g of anhydrous basis
After the sample was put in and degassed with a vacuum pump for a while, a predetermined acetaldehyde solution was added and vaporized. Then, after injecting air to return it to normal pressure, leave it in a constant temperature bath at 25 ° C. After 48 hours, the acetaldehyde concentration was measured with a gas detector tube.
When the equilibrium is reached, the relationship between the adsorbed amount of acetaldehyde and the concentration in the gas phase is investigated, the isotherm at 20 ° C is measured, and the gas concentration is measured.
The amount of adsorption at 10 ppm was calculated. The results are shown in Table 1.

[0041]

[Table 1]

The sample was placed in a plastic bag, sealed, and stored at 60 ° C. for 1 month, and the same test was conducted to measure the amount of adsorption. The measurement results are shown in Table 2.

[0043]

[Table 2]

As a result, the porous substance in which the metal acetate has been impregnated is
It can be seen that not only the initial acetaldehyde adsorption amount is high, but also the decrease in adsorption amount over time is small.

[0045]

The malodorous gas adsorbent of the present invention is one of the largest factors of malodorous components in the air, and is contained in cigarette smoke and the like, which cannot be sufficiently deodorized by conventional activated carbon. It is a deodorant that excels in adsorbing and removing aldehydes, especially acetaldehyde. Further, the purifying agent has a characteristic that not only the initial activity is high, but also the acetaldehyde adsorption rate does not decrease with the lapse of use time, and the effect can be maintained for a long time.

[Procedure amendment]

[Submission date] May 23, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

Claims (3)

[Claims] 1. A malodorous gas adsorbent comprising a porous substance impregnated with at least one metal acetate. 2. The malodorous gas adsorbent according to claim 1, wherein the porous substance is activated carbon. 3. The malodorous gas adsorbent according to claim 1, wherein the amount of metal acetate impregnated is 0.5 to 30 parts with respect to 100 parts of the porous substance.