JPH05138018A - Air purifying matter and production thereof - Google Patents

Abstract

PURPOSE:To provide a composition purifying contaminated air containing mal odorous gases represented by NH3 or H2S. CONSTITUTION:Air purifying matter is obtained by bonding a polymer complex to the surface of metallic iron or composed of an ferrous metal porous body derived from metallic iron. The air purifying matter is produced by adding a water-soluble polymer to an iron ion-containing aqueous solution with pH 6-11 to mix the same with said solution and supporting the resulting solution on metallic iron to dry the same. The iron ion-containing aqueous solution is prepared by adding one or more kind of basic matter selected from sodium hydroxide, calcium hydroxide and potassium hydroxide to an aqueous solution wherein one or more kind of an acid selected from sulfuric acid, hydrochloric acid, nitric acid, ascorbic acid, citric acid, tartaric acid, gluconic acid and tannic acid coexists.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purification product for purifying contaminated air containing odorous gases such as NH ₃ and H ₂ S, and a method for producing the same. The air-purified product of the present invention can be used, for example, as a household deodorant.

[0002]

As a method for treating malodorous gas in the air, for example, an adsorption method using activated carbon, a masking method using other fragrances, a chemical removal method for chemically reacting odors, or the like is used to reduce discomfort. Has been done. But,
The adsorption method using activated carbon has a problem that the deodorizing performance deteriorates in a short period of time. The masking method using other fragrances may not be a fundamental solution because the fragrance may cause new discomfort. As a chemical method of chemically reacting, there is, for example, a method of oxidizing and decomposing a malodorous gas with ozone, but excessive ozone is harmful to the human body and causes new harm. That is, it is difficult to control the amount of the chemical substance that reacts with the malodorous gas, so that an unnecessary chemical substance is generated, and it is hard to be a fundamental solution.

As a technique for solving these problems, Journal of the Textile Society of Japan (Fiber and Industry), Vol. 42 (1986). No.
12, P18 to 26, it is described that a complex compound obtained by reacting a ferrous compound and ascorbic acid in an aqueous solution has a deodorizing power for a nitrogen compound-based odorous gas.

However, according to the findings of the present inventors, there is a problem that this complex compound has a weak deodorizing power for sulfur compound type odorous gas. According to the findings of the present inventors,
This complex compound also has a problem that its deodorizing power deteriorates in a relatively short period of time. The present inventors have invented a composition in which a reaction product obtained by contacting ascorbic acid or the like with a metal such as iron or manganese coexists with unreacted iron or manganese,
A patent application was previously filed in Japanese Patent Application No. 1-280776. This composition can be manufactured at low cost, and the deterioration of the air cleaning power is extremely small, which solves the problems of the prior art.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
-280776 the composition of more extensively,
It is an object to provide a material having a new air cleaning power with a simpler process. In particular, there is a demand for a deodorant that improves the rate of CH ₃ SH (methyl mercaptan) removal and exerts the CH ₃ SH removal performance for a long period of time.

The composition of Japanese Patent Application No. 1-280776 tends to become brittle and powdery when dried, and when used as a deodorant, a sheet such as a non-woven fabric having air permeability and preventing scattering of powder is used. However, there was a problem that the original deodorizing performance could not be fully exerted.

[0007]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned problems, and is an air-purified product characterized in that a polymer complex is attached to the surface of metallic iron. It is also characterized in that the metallic iron is an iron-based metal porous body.

Further, a method for producing an air-purified product is characterized in that a water-soluble polymer is added to and mixed with an iron ion-containing aqueous solution having a pH of 6 to 11, and the aqueous solution is supported on the surface of metallic iron and dried. .. Here, the iron ion-containing aqueous solution is an aqueous solution coexisting with one or more acids selected from sulfuric acid, hydrochloric acid, nitric acid, ascorbic acid, citric acid, tartaric acid, gluconic acid, and tannic acid. , 1 selected from potassium hydroxide
Alternatively, it is also characterized in that two or more basic substances are added and mixed. Further, the water-soluble polymer is also characterized by being a vinyl acetate type or an acrylic type.

[0009]

According to the research conducted by the present inventors, NH ₃ and (CH
₃ ) The deodorizing performance of basic gas such as ₃ N (trimethylamine) is very well adsorbed on a metal complex which is a reaction product of a polybasic acid and a metal, but the adsorption power of CH ₃ SH gas is weak. One of the solutions is disclosed in Japanese Patent Application No. 63-2731.
This is a method of disposing a solid base as described in No. 95.

However, in the subsequent research, it was found that the substances having a strong adsorbing power for acidic gas such as H ₂ S are iron hydroxide and ferric oxide produced by dissolving metallic iron in an aqueous solution. We also found that it is necessary to form a state in which metallic iron and iron hydroxide, ferric oxide, and magnetite coexist in order to effectively produce iron hydroxide and continue its effect for a long period of time. .. Further, it was found that the substance having excellent H ₂ S removal performance was also excellent in CH ₃ SH removal performance.

The reason why the de-CH ₃ SH performance improves as the de-H ₂ S performance improves is considered to be that H of the --SH group has the same property as H ₂ S. Therefore, it can be inferred that it is effective to effectively generate iron hydroxide. However, studies by the present inventors have revealed that good de-H ₂ S performance is not a sufficient condition for good de-CH ₃ SH performance. For example, iron and L-ascorbic acid aqueous solution are brought into contact with each other in the air, and the complex salt produced and the coexisting substance of iron are heated at 150 ° C. for 2
The reaction product which has been heat-treated for 4 hours has very good H ₂ S removal performance, but somewhat inferior CH ₃ SH performance.

As a result of investigating various measures for improving the de-CH ₃ SH performance, a basic substance was added to an aqueous solution of an iron salt to adjust the pH to 6 to 11, and a polymer was added to the aqueous solution. By contacting it with metallic iron and drying it, it is extremely de-CH ₃ SH compared to the one without adding polymer
It was found that the composition changed to a composition with excellent performance. In addition, the composition produced does not disintegrate into powder due to the adhesion and shape-retaining effect of the polymer, and even when it is used as a deodorant, it can be used by directly exposing it to contaminated air. It has been found that can be greatly improved.

The water-soluble polymer is starch, which is a natural product, but carboxymethyl cellulose (CMC), which is widely used for various purposes such as clothes glue, is one of the most well known synthetic products. Further, as the synthetic resin type, there is a vinyl acetate type water-soluble polymer obtained by saponifying vinyl acetate with an alkali to form water-soluble polyvinyl alcohol (PVA). There are also acrylic resins treated in the same manner to be water-soluble, and these are used for adhesives and paints using water as a solvent. Furthermore, emulsions of various polymers, such as those in which fine particles of synthetic rubber are dispersed in water with an emulsifier, all fall into the water-soluble polymer referred to herein. Of these, particularly preferable water-soluble polymers include vinyl acetate-based and acrylic-based ones, and the addition amount thereof is an iron ion aqueous solution from the viewpoints of adhesion, shape-retaining effect, and reduction of deodorizing performance due to a film formed by the polymer. 0.5
It is preferable to be set to 8% by weight.

The concentration of iron ions in the aqueous solution of the present invention is preferably at least 0.1 mol / l in terms of deodorizing performance. Further, the pH is limited to a pH within a predetermined range in order to form the iron complex compound, but if this pH is less than 6, that is, if the acidity is strong, the adhesion by the polymer and the shape-retaining effect are weakened. Also, when the pH exceeds 11, that is, when the basicity becomes strong, adhesion by the polymer,
Shape retention effect does not appear.

De-CH ₃ S by adding polymer
Although the mechanism of the improvement effect of H performance has not been fully elucidated, iron-sulfur protein, that is, ferredoxin-type polymer complex is generated by the chemical reaction of the polymer and iron ion, and the stability of iron ion that becomes the active center of the redox catalyst is stabilized. It is presumed that this is the result of securing the sex. Next, examples of the present invention will be described.

[0016]

[Example] A fine porous iron powder of 10 μm under was applied to a urethane foam having a coarseness of 20 PPI and fired in a non-oxidizing atmosphere at 1150 ° C. for 2 hours to produce a porous iron body. 1
The size of each piece was about 90 mm × 80 mm × 10 mm, and the weight was about 40 g. The iron porous body was pickled with 1.5% hydrochloric acid, then washed with water and drained to give L- as shown in Table 1.
Immerse in an aqueous solution containing ascorbic acid, tannic acid, ferrous sulfate, ferrous chloride, calcium hydroxide, sodium hydroxide and polymer under various conditions,
A deodorizing filter was manufactured by naturally drying for a month. Table 1
The type of polymer inside is vinyl acetate for A and B, and p for A
The H used was 4 and the B used had a pH of 6.5. C, D,
E is acrylic, pH of C is 6.5, pH of D is 9,
The pH of E used was 7.2.

[0017]

[Table 1]

The deodorizing performance was investigated using a deodorizing test device, and the generation rate of powder due to vibration was also examined using a low tap vibrating screen. Figure 1 shows the deodorization test device.
As shown in, a circulation fan 2 having a blowing capacity of 400 l / min is installed in a 40 l closed container 1. 3 in the figure is a filter-like air purifier as a sample, 4
Is a gas inlet, 5 is a gas sampling port, and the gas is an arrow 6.
Circulate in the direction of.

First, the deNH ₃ performance was evaluated first, then the CH ₃ SH performance and the H ₂ S performance were evaluated in this order. Table 2 shows the evaluation results of the deodorization performance and the dust generation rate. It was
The numbers in this table correspond to the sample numbers in Table 1.
The deodorization rate was determined by measuring how much the concentration decreased 30 minutes after the initial concentration and the concentration ratio of the removed gas component. The dust generation rate was calculated by dividing the generated dust weight by the porous body weight. Almost all of the H ₂ S removal performance achieved a H ₂ S removal rate of 100% after 5 minutes, and the difference was not clarified.

[0020]

[Table 2]

As a result, not only the dust generation rate was lowered by the addition of the polymer, but also the deCH ₃ SH performance was greatly improved. Regarding the dust suppressing effect, the generation suppressing effect of ultrafine powder of 50 μm under is particularly remarkable.

[0022]

INDUSTRIAL APPLICABILITY According to the present invention, compared with the deodorant in which the reaction product of a metal such as iron and the polybasic acid such as ascorbic acid coexisted with the metal previously invented by the present inventors, a simple production method The performance could be further improved.

That is, a water-soluble polymer is added to and mixed with an iron ion-containing aqueous solution and supported on the surface of metallic iron to form a polymer complex, which improves the de-CH ₃ SH performance and eliminates the generation of powder. ..

[Brief description of drawings]

FIG. 1 is an explanatory view showing the structure of a test device for evaluating deodorizing performance.

Claims (5)

[Claims] 1. An air-purified product, characterized in that a polymer complex is attached to the surface of metallic iron. 2. The air-purified product according to claim 1, wherein the metallic iron is an iron-based metal porous body. 3. A method for producing an air-purified product, which comprises adding and mixing a water-soluble polymer to an iron ion-containing aqueous solution having a pH of 6 to 11 and supporting the aqueous solution on the surface of metallic iron for drying. 4. The iron ion-containing aqueous solution is sulfuric acid, hydrochloric acid, nitric acid, ascorbic acid, citric acid, tartaric acid, gluconic acid,
Claims characterized in that one or more basic substances selected from sodium hydroxide, calcium hydroxide and potassium hydroxide are added and mixed to an aqueous solution coexisting with one or more acids selected from tannic acid. Item 3. A method for producing an air-purified product according to Item 3. 5. The method for producing an air-purified product according to claim 3, wherein the water-soluble polymer is vinyl acetate-based or acrylic-based.