JPS58161904A - Composition for slowly generating gaseous chlorine dioxide - Google Patents

Abstract

PURPOSE:To obtain a composition capable of stably and slowly generating gaseous chlorine dioxide over a long term and suitable for use as a deodorant, a disinfectant, etc. by allowing a chlorite or stabilized chlorine dioxide and an alkaline oxidizing agent to be supported on or contained in an alkaline solid substance. CONSTITUTION:An alkaline solid substance of >=8pH such as aluminosilicate, magnesium silicate, calcium silicate or powdered silica gel is prepared. A chlorite such as sodium chlorite or calcium chlorite or stabilized chlorine dioxide and an alkaline oxidizing agent such as potassium permanganate or potassium dichromate are allowed to be supported on or contained in the solid substance to obtain the desired composition. The stabilized chlorine dioxide is obtd. by allowing gaseous chlorine dioxide to be absorbed in an aqueous soln. of hydrogen peroxide and sodium carbonate so as to adjust the chlorine dioxide concn. of the soln. to about 5% and the pH to about 9.

Description

[Detailed Description of the Invention] It is well known that small amounts of chlorine dioxide are effective as deodorizers, preservatives, antifungal agents, disinfectants, and disinfectants, and we have developed stabilized aqueous solutions of chlorine dioxide or Powdered or granular compositions that generate chlorine dioxide gas are commercially available as household or commercial products. The performance required of these products containing chlorine dioxide is that the contents do not change during the distribution or storage period of the product (remains stable), that it is easy and safe to use, that it is easy to use, and that the purpose of use is An effective amount of chlorine dioxide is effectively generated depending on the amount of chlorine dioxide.

Taking the use of such a product in a refrigerator as an example, the concentration of chlorine dioxide gas that is effective for deodorizing a refrigerator or for disaster prevention is approximately 0. O1 to 1.5PRn. If the concentration of chlorine dioxide gas is less than about 0.0 I PPm, the desired dehulling inside the refrigerator cannot be achieved sufficiently, and on the contrary, if the concentration of chlorine dioxide gas greatly exceeds about 1.5 PPmt, e.g. When the temperature reaches 5 to pPhl, the intended defruiting function is sufficiently achieved, but rather, when the refrigerator door is opened, the odor of excess chlorine dioxide ps is felt. However, the concentration of chlorine dioxide gas is 5 PP.
m or more, in addition to the deodorizing function, the disinfecting and sterilizing action of chlorine dioxide comes into play. For sterilization purposes, it is desirable to maintain the concentration of chlorine dioxide at about 5-15 PPm.

In addition to maintaining the concentration of chlorine dioxide gas at an appropriate level according to the purpose and function as described above, it is important that this concentration remains stable for a certain period of time. For example, if chlorine dioxide is consumed within a short period of time, such as one week, the gas generating powder bed must be replenished frequently.

The above means that chlorine dioxide gas is released not only in the refrigerator, but also in packaging packs for fresh foods such as vegetables, fruits, fish and shellfish, food display cases, the inside of cars, living rooms, kitchens, and washrooms. This applies to any place used for the purpose of environmental purification, such as anti-communicative, antiseptic, and sterilizing purposes.

It is well known that an aqueous solution containing chlorine dioxide is stable in an alkaline region, and commercially available stabilized chlorine dioxide aqueous solutions for sterilization and disinfection are adjusted to have a pH of 9 to 1O. This solution is
For example, gaseous chlorine dioxide is absorbed into an aqueous solution of hydrogen peroxide and sodium carbonate so that the concentration of chlorine dioxide in the total aqueous solution is about 5% and the pH of the aqueous solution is about 9.0%. This aqueous chlorine dioxide solution is activated in an acidic region, and the liberated chlorine dioxide acts as an appropriate oxidizing agent, exhibiting sterilizing and disinfecting effects.

The principle that chlorine dioxide-containing substances are stable in alkaline regions and activated in acidic regions to generate chlorine dioxide gas is also utilized in powdered or granular chlorine dioxide-containing compositions. Japanese Patent No. 72803
The composition described in No. 8 is based on this principle, and is a powdered solid composition in which an alkaline aqueous solution containing chlorine dioxide prepared as described above is adsorbed on an alkaline adsorbent having a pH of 8.5 to 9.0. This is the gist of the report. Since this composition is alkaline, it does not generate chlorine dioxide gas at this tt, and therefore, in this patent, when used, by mixing such a powder composition and an acidic powder substance, the entire composition is A method has been proposed in which chlorine dioxide gas is generated by lowering the pH value to 6 or less.

According to this method, it is possible to produce a chlorine dioxide-containing composition that can be stored in a stable state for a long period of time. On the other hand, chlorine dioxide gas is generated only when mixed with acidic powder during use, and the intended function of the product can be utilized. It is inconvenient for Furthermore, with this method, it is difficult to obtain a composition that stably generates a small amount of chlorine dioxide gas over a long period of time. Immediately after mixing the composition of this patent with acidic powder, a large amount of chlorine dioxide gas is generated, and stable gas generation is not observed over a long period of time, which limits its use.

The present invention solves the above-mentioned drawbacks of known chlorine dioxide gas generating compositions.1. The present invention provides a composition that can generate trace amounts of chlorine dioxide gas slowly and over a long period of time.

In the present invention, a salt containing chlorine dioxide is oxidized to generate chlorine dioxide gas even in an alkaline region in the presence of an alkaline substance with oxidizing ability supported on a basic solid powder, and the rate of generation is This is based on the knowledge that this is slow and persistent. That is, the gist of the present invention is to slowly generate chlorine dioxide gas, which is characterized by consisting of an alkaline solid substance with a pH of 8 or higher, a chlorite or stabilized chlorine dioxide supported or contained therein, and an alkaline oxidizing agent. In the composition.

Salts containing chlorine dioxide are chlorites of alkali or alkaline earth metals.・For example, Naclos, Kc
102, Lic102, Ca(clo2)ah Ba(
Clog)2, Mg(cloz)2, etc., but the most economical and practical substance is sodium chlorite.

Known stabilized chlorine dioxide can also be used in place of chlorite. In the presence of water and in an acidic system with a pH of 6 or less, these substances are
2), and this substance generates chlorine dioxide through a self-oxidation reaction, so lowering the pH of a composition containing chlorite to below 6 will temporarily generate a large amount of chlorine dioxide gas. . This is a drawback of known chlorine dioxide-containing compositions. However, in the composition of the present invention, in the alkaline range of pH 8 to 12, where chlorite is originally stable, in the presence of an alkaline substance having oxidizing ability, chlorite can be oxidized slowly and sustainably. I can make you do it.

In the present invention, various aluminosilicates, magnesium silicate, calcium silicate, powdered silica gel, etc. are used as the alkaline solid substance. These may be in granular form, but powdered ones are preferred. These may be either naturally occurring or synthetic, and a mixture of natural and synthetic may also be used. These solid powders preferably have a pH within the range of 8-12, but those with a pH of 8 or less can be prepared by adding an alkaline substance such as sodium carbonate, sodium bicarbonate, or calcium carbonate to bring the pH to the above alkaline range. can be used. Other properties required of the alkaline solid powder include adequate hygroscopicity and excellent processability such as granulation and solidification.

Examples of alkaline substances that can oxidize chlorite ions in alkaline regions include iron, chromium, 777'/
7. Solid or powdered oxides or hydroxides of lead, silver, mercury, bismuth, selenium, etc., alkali or alkaline earth metal oxyhalogen salts, permanganates, dichromates, etc. The substance is destroyed. These substances must be alkaline with a FiPH of 7 or higher. These alkaline substances may originally be contained in alkaline solid powders, but for solid powders that contain a small amount of these substances or do not contain these substances at all, an appropriate amount of oxidation may be necessary. It is necessary to add an alkaline substance with the ability. In the composition of the present invention, the required amount of these alkaline substances varies depending on the rate of chlorine dioxide gas generation required for the composition, but as a general guide, approximately 0
．． 1% to 20%, preferably 1% to 10%. Further, an amount of alkaline oxidizing agent exceeding the theoretical oxidation equivalent required to oxidize the chlorite contained in the composition to generate chlorine dioxide gas is unnecessary.

In producing the composition of the present invention, chlorite is adsorbed onto an alkaline solid powder containing an alkaline substance capable of oxidizing chlorite ions as described above. As the chlorite, an alkali or alkaline earth metal salt of chlorite is used, and sodium chlorite, which is the cheapest and most easily available, is generally used.

A powder or an aqueous solution containing the chlorite can be used, but an aqueous solution of the chlorite is preferable in order to uniformly mix it with the alkaline solid powder. This aqueous solution is N
a Alkaline substances such as CO and NaHCO 2 3
3 added as a stabilizer is also fine. As the aqueous solution of chlorite, an industrially produced solution can be used as it is or one diluted with water as appropriate.

It is of course possible to use a known stabilized chlorine dioxide aqueous solution in place of the chlorite aqueous solution. A stabilized chlorine dioxide aqueous solution can be produced by absorbing chlorine-free chlorine dioxide gas into an aqueous solution of an alkaline peroxygen compound, such as percarbonate, magnesium monoxide, calcium peroxide, or sodium peroxide. I can do it.

The above chlorite aqueous solution or stabilized chlorine dioxide aqueous solution is uniformly mixed with the above alkaline solid powder by a known method. This operation can be carried out, for example, while stirring the solid powder in a powder mixer. This can be carried out by gradually adsorbing or spraying the above aqueous solution.Next, it is preferable to dry this mixture. A composition is obtained. This drying can be carried out by any known suitable method, but drying can be carried out by s under normal pressure or reduced pressure.
It is preferable to carry out the reaction at a temperature of θ°C or lower. If a large amount of water remains, the stability of the composition will be poor.

Although one specific manufacturing process of the composition of the present invention has been described above,
The manufacturing process of the composition of the present invention is not limited to this, for example, the alkaline oxidizing agent may be supported or adsorbed after chlorite or stabilized chlorine dioxide is adsorbed onto the alkaline solid substance, Alternatively, when a composition in which chlorite or stabilized chlorine dioxide is supported or adsorbed on an alkaline solid substance and an alkaline solid substance in which an alkaline oxidizing agent is supported or adsorbed are mixed, the composition of the present invention can be obtained by J: You can also get it.

Unlike known compositions, the composition of the present invention generates chlorine dioxide gas slowly and continuously, and therefore can be used as a deodorizing or deodorizing agent, a preservative, a bactericide, a fungicide, a disinfectant, etc. It can be suitably used for various purposes. During use, moderate moisture in the air helps generate chlorine dioxide.

Next, specific implementation methods and effects of the present invention will be explained with reference to Examples. All percentages or proportions used in the examples represent weight percentages or weights.

Example 1 Natural magnesium/umum silicate with the following composition was used as solid powder raw material.

As SiO 41.0% ”203 tt 15.2Mg0 #
18.8 Fe203# 12. l CaOn 6.9 NaOJt O,3 to 20 # 0.7 Burning heat loss 50 +! L Particle size Passes below 2007 nm 100P of this material contains 7.3F of iron peroxide (Fe30.). While stirring this substance, PH1.1,
Add a 25% aqueous solution of sodium chlorite from No. 5 to the above substance No. 10.
0 parts to 24 parts were sprayed, mixed uniformly, and adsorbed. Next, this mixture was dried for 6 hours under a reduced pressure of 600 wHP at 80° C. or lower to obtain a powdery anhydride. This dry material contains 32,000 PPm of chlorine dioxide,
H was 9.8. This substance 10F was packaged in breathable paper and placed in an Ersinmeyer flask with a capacity of 300 cc, and the state of chlorine dioxide gas generation and pH were measured under conditions of a temperature of 6°C and 20% of the temperature. Got the results.

0 35
9.710
45 10.130
48
10.26G 55 1
0.090 30 9.6 Example 2 Synthetic calcium silicate having a pH of 9,01300 mesunyu or less was used as the alkaline solid powder. This substance is purified by metathesizing calcium metasilicate with calcium chloride. Uniform mixtures A, B, C and D were prepared by adding the following metal oxide powders to 100 parts of this material.

A Mn0299.9% 325 passed 3
Part B PbO99,99% rt 11t
tCFe2O, 98,0% #6 IID
Cr20396.0% II 5 1F
100 parts of each of the above mixtures and 40 parts of a stabilized chlorine dioxide aqueous solution containing 25% Cl0 were uniformly kneaded, heated to 60°C,
Dry for 3 hours under reduced pressure of 720 s + @HP. The dried shavings were crushed in a mortar to obtain a powder of 00 mesh or less.

The ClO2 content and jPH of these powders were as follows.

A I6.00G 9.38
1m1.000 9.0C17,6009,
@CI for each of the above powders under the same conditions as Example 1
When the state of O□ generation was observed, the following results were obtained.

Comparative Example 1 Same synthetic carunium silicate used in Example 2 100
20 parts of an aqueous solution of sodium chlorite having a pH of 11.5 and a concentration of 25% was sprayed on the sample to mix uniformly. The mixture was dried at 80° C. or below under a reduced pressure of 600 WoIIHy for 6 hours, and the dried product was pulverized to 300 mm or less. The C1O□ content of this powder is 31,300 pp, PH9
, I missed it at 2. This powder 1051 was placed in an Errenomeyer flask and the temperature was 8°C. When placed in a refrigerator with a humidity of 20% and observed for generation of chlorine dioxide, no generation of chlorine dioxide was observed even after 20 days.

The ClO2 content and PH of this product did not change after 20 days, and Example 3 1 part of the powder prepared in Comparative Example 1 was uniformly mixed with 2 parts of natural zeolite having the following composition.

As SiO 69.0 AI, 03 N 1 (1,□Mg
021/ 1a5 Fe203n 6,l CaOn 2.0PbOu
tt K20 If 1.0 This mixture 1
0y- was placed in an Erlenmeyer flask, and the temperature was 8°C.
When I placed it in a refrigerator with a humidity of 20% and observed the generation of chlorine dioxide, the following result was 0.
80 8.310
85
&330 110
&660
93 8.59
0 87
&3120 81
8.2 Example 4 Same synthetic carunium silicate used in Example 2 100
A homogeneous mixture E, F,
G was prepared.

E '10V1no 99.6% 6th part F
Cr0 96.0% 4II 3 G Ca (C10) 2” /298%
5 1/Composition prepared in Comparative Example 1 (ClO3-containing 1
3x, 3o.

Three types of compositions 61 obtained by uniformly mixing 1 part of each of the above mixtures E, F, and G with 1 part of powder (PPm, pH 9,2) were wrapped in breathable paper.
It was placed in an Ersinmeyer flask with a volume of 1300 cc, and the state of chlorine dioxide gas generation was measured in an atmosphere of about 60% temperature at 15° C., and the following results were obtained.

Comparative Example 2 10 parts of the powder prepared in Comparative Example 1 was mixed with 8 parts of a powder product in which synthetic calcium silicate powder and ferric chloride powder with a purity of 99.9% were uniformly mixed in a ratio of 1:1. did. The chlorine dioxide content of this mixture is 12,000PP
m Th PH was 5.5. Regarding this powder mixture, the state of generation of chlorine dioxide was observed under the same conditions as in Example 3.

As is clear from the above examples, the composition of the present invention in which chlorite or stabilized chlorine dioxide and an alkaline oxidizing agent are supported or adsorbed on an alkaline solid substance slowly and stably for a relatively long time. Generates chlorine dioxide. On the other hand, as seen in Comparative Example 1, no generation of chlorine dioxide was detected in the composition in which no alkaline oxidizing agent was present.

Furthermore, as shown in Comparative Example 2, in a composition to which an acidic substance is added, a large amount of chlorine dioxide gas is generated in a very short period of time, and the slow generation of chlorine dioxide cannot be maintained for a long period of time.

Patent Applicant: Mori 1) Kang, Fuo, Sui, Fuchio, Kao, Hiroyasu, Fuji, July 1, 1981, Mr. Kazuo Wakasugi, Director of the Japan Patent Office, who is blind, 1. Indication of the case, License No. 043706, 1982, Invention Name: Composition 3 that slowly generates chlorine dioxide gas Address of person making the correction: 2308-2 Shimonagatani-cho, Konan-ku, Yokohama, Kanagawa Prefecture
-101 & Subject of Amendment 6, the statement in the [Detailed Description of the Invention] of the Statement of Contents of the Amendment is corrected as follows.

Page Line Before correction After correction

Claims (1)

[Claims] A composition that slowly generates chlorine dioxide gas, comprising an alkaline solid substance with a pH of 8 or more, a chlorite or stabilized chlorine dioxide supported or contained therein, and an alkaline oxidizing agent.