JPH0138151B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a persistent chlorine dioxide volatile composition having the property of volatilizing chlorine dioxide little by little.

<Conventional technology and its problems> Recently, stabilized chlorine dioxide solution made by stabilizing chlorine dioxide in pure water or powdered stabilized chlorine dioxide have been used for various purposes as a source of chlorine dioxide. It is known that there are. Furthermore, compositions in which this stabilized chlorine dioxide solution is adsorbed onto porous materials or water-absorbing powders are also known. However, all of these have drawbacks such as short service life and lack of long-term storage, making them inconvenient to handle, and have not yet been put into practical use.

For example, the invention described in Japanese Patent Publication No. 48-32079 is
An example is disclosed in which a stabilized chlorine dioxide solution is adsorbed onto a basic water-absorbing powder to form a powdered chlorine dioxide composition, and furthermore, this powder composition is formed into a tablet or the like. However, judging from the contents of the publication, the main idea of this composition is to use it by mixing it with a solid acidic powder, or to use it as a deodorizing agent that is placed on top of acidic waste and activated by the waste. It is clear that this is the case.

That is, the powder composition disclosed in the above publication adsorbs an aqueous liquid containing chlorine dioxide suitable for generating gaseous chlorine dioxide by acidifying it to a pH lower than about 6 on a basic adsorbent powder; this,
In use, chlorine dioxide gas is generated by contacting with solid acidic powder as a chlorine dioxide generating agent or by utilizing the acidity of the waste, so it can be used for a long period of time, such as one month. Therefore, it cannot be used in applications where chlorine dioxide gas is gradually volatilized little by little. This means that 1/2 to 1/3 of the supported chlorine dioxide is generated in just 10 to 30 minutes after mixing the solid acidic powder, as shown in example ~ in the publication. It is clear from this.

Furthermore, in column 7, lines 1 to 4 of the same publication, there is a statement that the rate of generation of chlorine dioxide gas can be adjusted by adjusting the amount of acidic substance added or the strength of the acidic substance to be mixed. Even if the formulation is adjusted in this way, it is still within the scope of the technical concept of adding an acidic substance to activate the product before use. Moreover, as a result of the inventor's experiments, even if the amount of the acidic substance added or the strength of the acidic substance is adjusted, the mixture containing enough acidic substance to activate the chlorine dioxide liquid adsorption powder is 1 It has become clear that it cannot withstand long-term storage of more than a few months, and that it generates chlorine dioxide gas during storage.

In other words, there is a drawback that it is not possible to mix the solid acidic powder in advance before starting use and store it in a state ready for immediate use as a deodorant.

Next, the second composition of this patent publication No. 48-32079
The disadvantage of this is that it supports a relatively small amount of stabilized chlorine dioxide solution.

That is, the liquid absorption ability of the synthetic calcium silicate "Microcell E" manufactured by Johns, Mambire, and Corporation, which is particularly suitable in the same specification, is equivalent in weight ratio based on the results of the examples of the same invention and the experiments conducted by the present inventor. It has become clear that the amount (100%) is the limit, and if you try to adsorb more than this, it will become muddy.

As is well known, the greater the liquid absorption capacity of a carrier, the larger the amount of available chlorine dioxide it will contain, so using a carrier with as large a liquid absorption capacity as possible as an adsorption carrier will increase the longevity and effectiveness of the resulting composition. In this respect, there remained room for improvement in this powder composition.

Furthermore, the same specification states that the powder composition of the present invention can be pressure-molded into tablets, etc. However, as a result of study by the present inventor, the following drawbacks regarding pressure-molding are found: It was found that this is disadvantageous as a stable volatile composition for chlorine dioxide. That is, first of all, after forming a powder composition, it is exposed to open air during the process of pressure molding into tablets, etc., so chlorine dioxide volatilizes, and the effective chlorine dioxide content in the resulting molded product decreases. decrease,
Secondly, as is well known, chlorine dioxide gas is a metal,
In particular, since it has the effect of rusting iron products, it corrodes the plating of the mold during molding, and iron rust forms on the internal iron surface, which mixes into the molded product and decomposes the stabilized chlorine dioxide solution it contains. Third, it is known that compounds of chlorine and oxygen, such as chlorites and hypochlorites, decompose explosively due to friction, pressure, and impact. Therefore, compression tableting on an industrial scale is dangerous and undesirable.

In summary, the chlorine dioxide composition disclosed in Japanese Patent Publication No. 48-32079 is primarily intended to generate chlorine dioxide gas by adding an acidic solid substance at the time of use. It is not suitable for volatilizing small amounts of chlorine dioxide gas over a long period of time.Secondly, if it is stored in a state in which solid acidic powder is mixed in advance, it can be stored as long as the amount and strength of the acidic substance is sufficient to activate it. The third problem is that chlorine dioxide gas is generated in the product, making it impossible to store it for a long time (on the contrary, it cannot be activated by adding an acidic substance that can be stored for a long time), and thirdly, the ability to support a stable chlorine dioxide solution is Fourthly, it is as low as 100% by weight.
When this powder composition is compressed into tablets,
The effective content of chlorine dioxide decreases due to gas volatilization during the molding process, and storage stability deteriorates due to iron rust and operational safety becomes a problem.
There were drawbacks such as: Therefore, this powder composition has a deodorizing effect by continuously volatilizing small amounts of chlorine dioxide gas over a long period of one to three months in a relatively tightly closed space such as a refrigerator or shoe cabinet. Furthermore, no other solid composition has been proposed that can stably hold a stabilized chlorine dioxide solution and achieve the above objective.

This is because it is common knowledge that chlorine dioxide gas will not be generated when a stabilized chlorine dioxide solution is adsorbed onto a carrier and made solid, unless it is activated by adding an acidic substance. It is presumed that this was because no one had tried it because it had been formed from other prior documents.

<Means for Solving the Problems> In order to solve the inconvenience of handling stabilized chlorine dioxide liquid because it is in liquid form, the present inventor has been researching its solidification and adsorption carrier for many years. Surprisingly, by selecting an appropriate adsorption carrier, the carrier supporting the stabilized chlorine dioxide solution has the property of gradually volatilizing chlorine dioxide gas little by little without the action of acidic substances. In addition, they discovered that the iron content in the carrier is involved in the rate of volatilization, and succeeded in overcoming the drawbacks of conventional products, leading to the completion of the present invention.

That is, the composition of the present invention can be used as an adsorption carrier to
A synthetic calcium silicate powder with a petal-shaped crystal structure that can adsorb and support 280% by weight of a stabilized chlorine dioxide solution is made into a molded product, and a stabilized chlorine dioxide solution is adsorbed and supported on this powder without mixing acidic compounds. This composition is characterized by having the property of volatilizing chlorine dioxide gas little by little over a long period of time when used alone, and is useful for deodorization and use mainly in highly airtight spaces such as refrigerators and shoe cabinets. The purpose is to provide a fungicide.

<Function> The composition of the present invention has the following effects and features not found in conventional products.

In other words, since the only step is to adsorb the stabilized chlorine dioxide solution onto the molded product, there is no volatilization loss compared to when compression molding is performed in the open after adsorption onto the powder, and most of the adsorbed liquid is removed. It is recommended to store it in a gas barrier bag because it has a long service life because it can be carried as is without any loss, and secondly, there is no risk of accelerating the decomposition of chlorine dioxide due to contamination by foreign matter during the molding process, especially iron rust. For example, it can withstand long-term storage of about one year.

The calcium silicate molded product with a petal-like crystal structure used in the present invention (hereinafter referred to as a calcium silicate molded product) is produced by producing calcium silicate with a petal-like crystal structure with a length of 1 to 5 μm.
It can be used by forming it into a sphere or the like using a wet cake process and drying it. The pH of the calcium silicate obtained in this way is about 9.2 to 9.4 (measured with a 5% slurry liquid), but calcium silicate that has been mixed with 30% by weight or less of sulfuric acid during the manufacturing process to lower the pH to 7.6 to 8.0 is also used. Can be used. Calcium silicate, which has a scale-like or fibrous crystal structure, has a poor ability to adsorb and retain a stabilized chlorine dioxide solution, so it is disadvantageous to use it alone.

As mentioned above, as a result of many experiments, the present inventor found that
It has been found that the higher the content of iron compounds present in the carrier, the faster the chlorine dioxide volatilizes from the composition of the present invention, resulting in a stronger oxidizing effect, but on the other hand, the volatilization life is shorter. In the present invention, the amount of iron compounds in the calcium silicate molded product is adjusted to Fe ₂ O ₃ in consideration of the balance between the effect of chlorine dioxide and the volatilization life described above.
The content is limited to 0.2% by weight or less. 0.2
If it exceeds % by weight, chlorine dioxide volatilizes relatively quickly and lacks the property of stably volatilizing little by little, so it is excluded from the present invention. The iron content in normally obtained calcium silicate molded products is expressed as Fe ₂ O ₃ .
It is in the range of 0.01 to 0.03% by weight, and if this adsorption carrier is used as it is, the volatilization of chlorine dioxide from the adsorbed stabilized chlorine dioxide liquid is very small and occurs very gradually, so if you want to accelerate the volatilization of chlorine dioxide, In accordance with the above experimental results, an iron salt aqueous solution such as an iron sulfate aqueous solution was adsorbed in an amount of 0.02 to 0.18% by weight as Fe ₂ O ₃ to the calcium silicate molded article in advance, or
Alternatively, it is possible to adopt a method such as sprinkling fine powder of iron oxide on the surface of a calcium silicate molded product on which a liquid has been adsorbed during use. There are no particular restrictions on the type and concentration of the iron salt aqueous solution used in this case, as long as it is not acidic.

The stabilized chlorine dioxide solution used in the present invention differs from chlorine dioxide water in which chlorine dioxide is simply dissolved in water, and is made by absorbing chlorine dioxide gas into a peroxide such as soda percarbonate to form a complex salt. It is stably retained and dissolved in water, and an example of its manufacturing method is disclosed in, for example, US Pat. No. 3,123,521.

In the present invention, not only the liquid stabilized by the method described in the above-mentioned US patent specification but also a chlorine dioxide liquid stabilized by other methods can be used.

These stabilized chlorine dioxide solutions usually contain 5% by weight.
The remaining 95% by weight is water, so when the chlorine dioxide gas it contains evaporates, it becomes an aqueous solution of soda carbonate, which is different from what is called a volatile liquid in chemical conventions. be.

Next, in the composition of the present invention, the ratio of the stabilized chlorine dioxide solution to the calcium silicate molded product ranges from 10 to 280 parts by weight of the stabilized chlorine dioxide solution to 100 parts by weight of the calcium silicate molded product, depending on its use. You may choose as appropriate. If the amount is less than 10 parts by weight, the period of effectiveness will be short, and if it is more than 280 parts by weight, the adsorption capacity will be exceeded and therefore it is outside the scope of the present invention. There are no particular restrictions on the concentration of the stabilized chlorine dioxide solution used, but
Usually, a solution of 100ppm (0.01%) to 50000ppm (5%) is used.

The composition of the present invention has the property of continuously volatilizing chlorine dioxide little by little while containing about 75% by weight of the stabilized chlorine dioxide solution of its own weight, and the amount of the volatilization is equal to the amount of iron compound contained in the carrier. It has the great feature of being able to be controlled by chlorine dioxide, and can be used for a variety of purposes as a source of small amounts of chlorine dioxide that is easy to handle. For example, freshness preservation agents during transportation and storage of fruits and vegetables, fungicides in rooms, etc.
It can be used as a deodorizing agent in a relatively tightly closed environment, and its long durability is a feature not found in conventional products.

<Example> Examples will be shown below, and all parts are shown in parts by weight.

Example 1 Commercially available petal-shaped calcium silicate spherical molded product (trade name Fluorite R, 3 to 10 mmφ, Fe ₂ O ₃ content
0.03% by weight, Tokuyama Soda Co., Ltd. product) 100 copies
280 parts of a 10,000 ppm stabilized chlorine dioxide solution was added dropwise and adsorbed to obtain a composition of the present invention. When 60 parts of the composition thus obtained was stored in a breathable nonwoven fabric and placed in the upper part of a 120-capacity refrigerator, the deodorizing effect was maintained even after about 40 days.

Example 2 A 3 to 5 mmφ spherical molded product of petal-shaped calcium silicate to which sulfuric acid was added (trade name: Fluorite)
RN, Fe ₂ O ₃ content 0.03% by weight, manufactured by Tokuyama Soda Co., Ltd.) was adsorbed in advance with a ferrous sulfate aqueous solution to make the iron content 0.08% by weight as Fe ₂ O ₃ .
Adsorb 10 parts of 50,000 ppm stabilized chlorine dioxide solution to 100 parts. Composition 10 of the present invention thus obtained
Place the parts in a breathable non-woven fabric and fix them to the inner wall of a cardboard box containing 10 oranges. Mandarin oranges as a control box
Prepare a cardboard box of the same size containing 10 pieces. After 7 and 21 days of storing these boxes indoors at 15 to 18°C, we compared the freshness of the oranges and the occurrence of mold on the epidermis. The control box maintained its freshness with only 1 mold forming on the skin, compared to 10 cases in the control box.
Mold developed on the skin of seven of the eggs, and there was no freshness all over, and the freshness had clearly decreased.

Reference Example The following powder composition was prepared according to the formulation of the example in Japanese Patent Publication No. 48-32079.

Dissolve sodium chlorite (manufactured by Wako Pure Chemical Industries, Ltd., special grade reagent) in water to make a 6% solution, and add sodium bicarbonate (manufactured by Wako Pure Chemical Industries, Ltd., special grade reagent) to this to bring the pH to 8.5. It was adjusted to Johns,
Synthetic calcium silicate "Microcell E" commercially available from Mambire Corporation (importer,
100 parts of the above solution (solution to powder ratio 1:1) was adsorbed onto 100 parts of Tokyo Kogyo Trading Co., Ltd.).

On the other hand, for 100 copies of the above "Microcell E"
Prepare acidic powder by adsorbing 100 parts of 30% ferric chloride solution (1:1 ratio).

A mixture of 100 parts of this acidic powder and 100 parts of the above-mentioned chlorine dioxide-containing powder composition is approximately 2 to 3
Minutes later, the odor of chlorine dioxide gas was felt. 200 parts of this mixture and 200 parts of the volatile composition obtained in Example 1 of the present invention were placed in separate containers with open tops and allowed to stand in a room temperature room to reduce the amount of chlorine dioxide in the composition over time. When the residual rate (incidence rate) was measured, the results shown in the figure were obtained.

The residual rate of chlorine dioxide was measured by taking a fixed amount of a sample every time and using the conventional iodine method.

From these results, it was found that the composition of the present invention gradually volatilizes chlorine dioxide gas over a long period of time without adding acidic compounds, whereas the composition of Japanese Patent Publication No. 48-32079 volatilizes about 60% of chlorine dioxide in one day. However, it became clear that most of it had evaporated after 5 days.

That is, from now on, the composition of the present invention and the
It was found that there was a clear difference in the mechanism of chlorine dioxide gas generation from the composition of No. 32079.

[Brief explanation of drawings]

The figure is a graph showing the residual rate of chlorine dioxide in the composition over time.

Claims (1)

[Scope of Claims] 1. A calcium silicate molded product having a petal-like crystal structure and having an iron content of 0.2% by weight or less as Fe ₂ O ₃
A chlorine dioxide volatile composition characterized in that 10 to 280 parts by weight of a stabilized chlorine dioxide solution is adsorbed onto 100 parts by weight. 2 A calcium silicate molded product with a petal-shaped crystal structure with an iron content of 0.2% by weight or less as Fe ₂ O ₃ can reduce its iron content to Fe ₂ O ₃ by adsorbing a non-acidic iron salt aqueous solution. as 0.02~0.2% by weight
The chlorine dioxide volatile composition according to claim 1, which is a molded calcium silicate having a petal-like crystal structure.