KR102093907B1 - A composition for providing room temperature long-term constant-concentration chlorine dioxide solution in aqueous medium and preparation method thereof - Google Patents

Abstract

Dissolved chlorine dioxide; An inhibitor of decomposition of the dissolved chlorine dioxide; And a pH adjusting agent, a long-term concentration maintenance chlorine dioxide aqueous solution composition and a method for manufacturing the same are provided.

Description

Maintaining a long-term concentration at room temperature Aqueous solution of chlorine dioxide and its manufacturing method {A COMPOSITION FOR PROVIDING ROOM TEMPERATURE LONG-TERM CONSTANT-CONCENTRATION CHLORINE DIOXIDE SOLUTION IN AQUEOUS MEDIUM AND PREPARATION METHOD THEREOF}

The present invention relates to a chlorine dioxide aqueous solution composition for maintaining a long-term concentration at room temperature and a method for manufacturing the same.

Chlorine dioxide was discovered by Sir Humphrey Dary in 1811, and has a melting point of -59 ° C and a boiling point of 11 ° C and is a greenish-yellow gas at room temperature. Chlorine dioxide has a mild chlorine odor and is soluble in water and ether. Chlorine dioxide has a strong oxidizing power (oxidation state: +4) and provides a sterilizing effect.

Chlorine dioxide was first applied to water treatment facilities in Niagara Falls, New York State in 1944, and is now widely used as a disinfectant in the United States and Europe. Chlorine dioxide is recognized as a disinfectant disinfectant in Korea by the Ministry of Environment, 1999-173 (1ppm or less), and the chlorine dioxide produced by the Food and Drug Safety Notification No. 2007-74 through the chlorine dioxide water production device Used for sterilization purposes.

Sodium hypochlorite aqueous solution (so-called "Lax"), a chlorine-based disinfectant widely used in homes, reacts with organic substances to cause carcinogens such as trihalomethane (THM), haloacetic acids (HAAs), and others. It produces chlorinated organic compounds.

Chlorine dioxide does not oxidize organics and therefore does not produce carcinogens, trihalomethane (THM), haloacetic acids (HAAs), and other chlorinated organic compounds. In addition, chlorine dioxide has a sterilizing effect in a wide pH range, and is easily decomposed by light, thereby being environmentally friendly.

Chlorine dioxide is unstable at room temperature and decomposes into ClO _2- , ClO _3- , Cl-, etc. For example, as a result of analyzing high-concentration chlorine dioxide aqueous solutions provided at three water purification plants in Gyeonggi-do, the disinfecting power was very weak, and most of the substances causing cyanosis were present, and the residual chlorine dioxide content was also very low (Analytical Science & Tech., Vol. 12) , Pp. 403-407, 1999).

Therefore, there is a need for a composition comprising chlorine dioxide capable of maintaining a long-term concentration at room temperature that can be stored and / or distributed for a long time.

One aspect is to provide a new long-term concentration maintenance chlorine dioxide aqueous solution composition.

Another aspect is to provide a method for preparing a long-term concentration-maintaining chlorine dioxide aqueous solution composition.

According to one aspect,

Dissolved chlorine dioxide;

An inhibitor of decomposition of the dissolved chlorine dioxide; And

Provided is a long-term concentration maintenance aqueous chlorine dioxide aqueous solution composition comprising a pH adjusting agent.

According to the other aspect,

Preparing a first solution containing dissolved chlorine dioxide; And

A method for preparing a long-term concentration-maintaining chlorine dioxide aqueous solution composition is provided, comprising adding a long-term concentration-maintaining agent including a decomposition inhibitor of chlorine dioxide and a pH adjusting agent to the first solution.

According to one aspect, by maintaining a long-term concentration maintaining agent including a decomposition inhibitor of chlorine dioxide and a pH adjusting agent, the ability to maintain the long-term concentration at room temperature of the aqueous chlorine dioxide solution is improved.

Hereinafter, a long-term concentration maintenance chlorine dioxide aqueous solution composition and a method for manufacturing the same according to an exemplary embodiment will be described in more detail.

In addition, hereinafter "long-term concentration maintenance or stabilization" means having a long-term concentration maintenance efficacy of 6 months or more, preferably 1 year or more.

The creative idea disclosed in the present specification can apply various transformations and have various implementations, so that specific implementations are described in detail in the detailed description and specific implementations are illustrated when necessary. Effects and features of the creative ideas of the present specification and methods for achieving them will be clarified with reference to implementations described below in detail. However, the creative spirit of the present specification is not limited to the embodiments disclosed below and may be implemented in various forms.

In the following embodiments, terms such as first and second are used for the purpose of distinguishing one component from other components, not limited meanings.

In the following embodiments, singular expressions include plural expressions, unless the context clearly indicates otherwise.

In the following embodiments, terms such as include or have mean that a feature or component described in the specification is present, and does not preclude the possibility that one or more other features or components may be added.

When one embodiment can be implemented differently, a specific process order may be performed differently from the described order. For example, two processes described in succession may be performed substantially simultaneously, or may be performed in an order opposite to that described.

Chlorine dioxide decomposes over time in aqueous solutions. The conventional method for suppressing the decomposition of chlorine dioxide is, for example, as follows.

This is a method of producing chlorine dioxide as shown in Reaction Scheme 1 below by storing in a basic sodium chlorite (NaClO ₂ ) aqueous solution and adding an acid using a device or equipment immediately before use. In this method, since sodium chlorite (NaClO ₂ ) solution itself has little chlorine dioxide, desired sterilization and deodorization efficacy cannot be expected, and a mechanism or facility for generating chlorine dioxide is expensive, and most of all, dioxide generated The chlorine concentration cannot be constantly controlled and / or maintained.

<Scheme 1>

5NaClO ₂ + 4HCl → 4ClO ₂ + 5NaCl + 2H ₂ O

Methods for preserving the concentration of chlorine dioxide for about 14 days by adding organic acids such as formic acid and citric acid to chloric acid are disclosed in Korean Patent Publication Nos. 2009-0132993 and Korean Patent Publication 2007-0028405.

As a method of preserving a halogen dioxide solution by removing hydroxide ions, by including a hydroxide ion remover, hydroxy containing 0.001% to 10% of hydroxide ions based on the total weight of the halogen dioxide precursor solution A method for removing ions is disclosed in Korean Patent Publication No. 2006-0009355.

A method of preserving chlorine dioxide by adding citric acid in a therapeutic ophthalmic composition is disclosed in Korean Patent Publication No. 2007-0028405.

However, these methods lack the effect of inhibiting the decomposition of chlorine dioxide for a long period of time of 6 months or longer.

Long-term concentration maintenance chlorine dioxide aqueous solution composition according to one embodiment is dissolved chlorine dioxide; Inhibitors of decomposition of dissolved chlorine dioxide; And pH adjusting agents.

Maintaining a long-term concentration The decomposition of chlorine dioxide is suppressed by the aqueous chlorine dioxide aqueous solution composition containing an inhibitor of decomposition of dissolved chlorine dioxide, so that the dissolved chlorine dioxide is maintained at a concentration for a long period of time of 6 months or more, preferably 12 months or more.

The inhibitor of decomposition of dissolved chlorine dioxide plays a role in inhibiting the decomposition of dissolved chlorine dioxide by positive reaction. Therefore, the concentration of chlorine dioxide can be kept constant for a long period of time. The decomposition inhibitor of dissolved chlorine dioxide may be the result of a positive reaction of chlorine dioxide.

For example, as shown in Reaction Scheme a below, in the reversible reaction, the forward reaction and the reverse reaction proceed simultaneously. Reactants A and B produce C and D by forward reaction, and products C and D are reduced to products A and B by reverse reaction. Since only reactants A and B are present at the beginning of the reaction, the forward reaction mainly occurs, but when the amount of products C and D increases, the reverse reaction also increases. As a result, a chemical equilibrium is reached in which forward and reverse reactions proceed at the same rate.

In chemical equilibrium, the concentrations of reactants and products are constant and there is no change in concentration over time.

<Scheme a>

A + B ↔ C + D

Therefore, when the products C and D are added to the composition containing A and B, the chemical equilibrium is initially reached and the decrease in concentration due to the positive reaction of A and B is suppressed. In addition, when A and B are added to the composition containing A and B in an amount greater than the amount of C and D that can be generated from the positive reaction of A and B, A and B are increased by the reverse reaction, so A and / or A decrease in concentration due to side reactions such as decomposition of B can be suppressed for a long time.

Maintaining a long-term concentration In the chlorine dioxide aqueous solution composition, the initial content of the decomposition inhibitor may be 10% or more of the initial content of dissolved chlorine dioxide. That is, the initial content of chlorine dioxide, the initial content of the decomposition inhibitor, which is the result of the positive reaction of chlorine dioxide, is 10% or more, thereby preventing the concentration reduction due to side reactions such as vaporization of chlorine dioxide. For example, the initial weight ratio of dissolved chlorine dioxide and the decomposition inhibitor may be 1: 0.1 to 10, 1: 0.2 to 10, 1: 0.5 to 10, 1: 1 to 10, and 1: 2 to 1:10. The stability of the dissolved chlorine dioxide can be further improved by the dissolved chlorine dioxide and the decomposition inhibitor having an initial weight ratio in this range. The initial weight ratio is a weight ratio of dissolved chlorine dioxide and a decomposition inhibitor when preparing a long-term concentration-maintaining chlorine dioxide aqueous solution composition.

Maintaining long-term concentration In the aqueous chlorine dioxide aqueous solution composition, dissolved chlorine dioxide and a decomposition inhibitor are separately prepared. That is, the dissolved chlorine dioxide contained in the chlorine dioxide aqueous solution composition for maintaining a long-term concentration is not only the dissolved chlorine dioxide generated by adding an acid to the chlorite and / or hypochlorite solution, but also separately for the production of a long-term concentration-maintained chlorine dioxide aqueous solution. These include those derived from the prepared chlorine dioxide.

Maintaining a long-term concentration In the aqueous chlorine dioxide aqueous solution composition, the decomposition inhibitors include chlorate and chlorite.

Chlorine dioxide reacts with water at room temperature to decompose chlorine dioxide, producing chloric acid and chlorous acid as shown in Reaction Scheme 2 below.

<Reaction Scheme 2>

2ClO ₂ + H ₂ O ↔ HClO ₂ + HClO ₃

Since chlorine dioxide (HClO ₂ ) or chloric acid (HClO ₃ ) is more thermodynamically stable than chlorine dioxide (ClO ₂ ), the forward reaction proceeds slowly or rapidly depending on the conditions. After a long period of time, all chlorine dioxide is decomposed into chlorous acid and chloric acid.

Therefore, the chlorine dioxide aqueous solution composition reaches a chemical equilibrium by adding chloric acid and chloric acid to the aqueous chlorine dioxide aqueous solution composition before chlorine dioxide is decomposed, so that the concentration decrease with time due to the positive reaction of chlorine dioxide is suppressed.

As a reaction inhibitor, chlorate and chlorite are added, and chlorate and chlorite are converted to chloric acid and chloric acid, respectively, as shown in Reaction Schemes 3 and 4 below by maintaining an acidic atmosphere by a pH adjusting agent.

<Scheme 3>

NaClO ₃ + H ⁺ → Na ⁺ + HClO ₃

<Reaction Scheme 4>

NaClO ₂ + H ⁺ → Na ⁺ + HClO ₂

The converted chloric acid and chlorous acid can maintain the concentration of chlorine dioxide for a long period of time by inhibiting chlorine dioxide decomposition in Reaction Scheme 2 as described above.

Maintaining a long-term concentration In the aqueous chlorine dioxide aqueous solution composition, the initial weight ratio of chlorate and chlorite is 1: 9 to 9: 1, 2: 8 to 8: 2, 3: 7 to 7: 3, or 4: 6 to 6: 4 days You can. The stability of dissolved chlorine dioxide can be further improved by the fact that chlorate and chlorite have an initial weight ratio in this range. The initial weight ratio is a weight ratio of chlorate and chlorite added during the preparation of a long-term concentration maintaining chlorine dioxide aqueous solution composition.

Maintaining a long-term concentration In the chlorine dioxide aqueous solution composition, the chlorate may include at least one selected from alkali metal chlorate and alkali metal chlorate. For example, the chlorate salt may include one or more selected from sodium chlorate, potassium chlorate, lithium chlorate, calcium chlorate, magnesium chlorate, and barium chlorate. In particular, the chlorate salt may be sodium chlorate and / or potassium chlorate.

Maintaining a long-term concentration In the aqueous chlorine dioxide aqueous solution composition, the chlorite may include at least one selected from alkali metal chlorite and alkali metal chlorite. For example, the chlorite may include one or more selected from sodium chlorite, potassium chlorite, lithium chlorite, calcium chlorite, magnesium chlorite, and barium chlorite. In particular, the chlorite can be sodium chlorite and / or potassium chlorite.

Maintaining a long-term concentration The chlorine dioxide aqueous solution composition may further include hypochlorite. By further including hypochlorite, the hypochlorite can be reacted with chloric acid and water according to Scheme 5 below to additionally produce chlorine dioxide.

<Scheme 5>

2NaClO ₂ + NaClO + 2HCl → 2ClO ₂ + 3NaCl + H ₂ O

Maintaining a long-term concentration In the chlorine dioxide aqueous solution composition, the initial content of hypochlorite may be 2 wt% or less, 1 wt% or less, 0.5 wt% or less, 0.2 wt% or less, 0.1 wt% or less based on the total weight of the chlorine dioxide aqueous solution. The stability of dissolved chlorine dioxide can be further improved by the hypochlorite having an initial content in this range. The initial content is the content of hypochlorite added during preparation of a long-term concentration-maintaining chlorine dioxide aqueous solution composition.

Maintaining a long-term concentration The pH adjusting agent included in the chlorine dioxide aqueous solution composition may be phosphoric acid or a salt thereof. For example, the pH adjusting agent may be sodium dihydrogen phosphate or a mixture of sodium dihydrogen phosphate and sodium monohydrogen phosphate, but is not limited thereto, and may be any material capable of maintaining a constant pH of the composition in the art. Do.

Maintaining a long-term concentration The pH of the aqueous chlorine dioxide solution composition may range from 2 to 6.9, and from 2 to 6.5. Long-term concentration-maintaining chlorine dioxide aqueous solution composition has an acidic or weakly acidic atmosphere in this range, so that chlorate, chlorite and / or hypochlorite contained in long-term concentration-maintaining chlorine dioxide aqueous solution composition is converted to chloric acid, chloric acid and / or hypochlorous acid It can be used for suppression of positive reactions and / or chlorine dioxide production reactions.

The content of dissolved chlorine dioxide contained in the long-term concentration maintenance chlorine dioxide aqueous solution composition may be 1 to 5000 ppm, 1 to 4000 ppm, 1 to 3000 ppm, 1 to 2500 ppm, or 1 to 2000 ppm. Maintaining a long-term concentration The aqueous chlorine dioxide composition may have a dissolved chlorine dioxide content in this range, thereby improving the stability of chlorine dioxide, but it is not necessarily limited to this range, and a greater amount of dissolved content is required depending on the use of the required composition. Chlorine dioxide.

Maintaining a long-term concentration In the aqueous chlorine dioxide aqueous solution composition, for example, the decomposition inhibitor may be sodium chlorate and sodium chlorite, and the pH adjusting agent may be a mixture of sodium dihydrogenphosphate and sodium monohydrogenphosphate. Maintaining a long-term concentration The aqueous chlorine dioxide aqueous composition may further improve the stability of dissolved chlorine dioxide by having such a specific decomposition inhibitor and pH adjusting agent.

Maintaining long-term concentration In the aqueous chlorine dioxide aqueous solution composition, the content of dissolved chlorine dioxide remaining in the composition after 1 year from the preparation of the composition is 90% or more, 92% or more, 94% or more, 96% or more of the initial dissolved chlorine dioxide content, or 98% or more. Maintaining a long-term concentration Chlorine dioxide aqueous solution composition can be effectively used in various applications by maintaining such a high concentration of chlorine dioxide even after a long period of time.

Long-term concentration maintenance Chlorine dioxide aqueous solution composition can be used for a variety of applications. For example, apartments, public buildings, toilets, pulp bleaching, disinfectants or biocides for municipal and industrial water, cooling towers, swimming pools, small food and beverage facilities, greenhouses, livestock, oil pollution measures, oilfield treatment, fumigation, medicine It can be used in laboratories and facilities, but is not limited to these, and any field requiring sterilization and / or disinfection is possible.

Method for preparing a long-term concentration maintenance chlorine dioxide aqueous solution composition according to another embodiment, preparing a first solution containing dissolved chlorine dioxide; And adding a long-term concentration maintaining agent including a decomposition inhibitor of chlorine dioxide and a pH adjusting agent to the first solution.

The method for preparing the first solution containing dissolved chlorine dioxide is not particularly limited, and any method and / or apparatus for manufacturing chlorine dioxide in the art may be used.

The first solution containing dissolved chlorine dioxide is prepared, for example, by the following method.

First, as a method for producing chlorine dioxide, when producing hundreds of tons of chlorine dioxide per day in an acidic liquid phase (ultra-large production method), the starting material chlorate as shown in Reaction Scheme 6 is SO ₂ , HCl, CH ₃ OH, etc. It is produced using a reducing agent.

<Scheme 6>

2NaClO ₃ + H ₂ SO ₃ → 2ClO ₂ + Na ₂ SO ₄ + H ₂ O

However, this method requires a large amount of equipment and is difficult to apply other than the bleaching process.

Next, as a method for preparing chlorine dioxide, when producing as tens of kilograms of chlorine dioxide per day, chlorine dioxide is prepared by oxidizing general inorganic acids such as HCl and H ₂ SO ₄ and chlorite as shown in Scheme 1 below.

<Scheme 1>

5NaClO ₂ + 4HCl → 4ClO ₂ + 5NaCl + 2H ₂ O

This method is simple to manufacture, but only 80% of the reactant chlorite participates in the reaction, excessive impurities are produced, and the purity and yield of the produced diacid and chlorine are low.

Alternatively, as a method for preparing chlorine dioxide, chlorine dioxide is prepared by reacting a chlorite salt with a persulfate salt as shown in Reaction Scheme 7 below.

<Scheme 7>

2NaClO ₂ + Na ₂ SO ₄ → 2ClO ₂ + 2Na ₂ SO ₄

Alternatively, as a method for preparing chlorine dioxide, chlorine dioxide is prepared by reacting chlorite, hydrochloric acid, and hypochlorite as in Scheme 8 below.

<Scheme 8>

2NaClO ₂ + NaClO + 2HCl → 2ClO ₂ + 3NaCl + H ₂ O

Although this method has high purity, it is complicated and requires a lot of raw material storage containers because three raw materials are added.

Alternatively, as a method for preparing chlorine dioxide, chloric acid, an acid and a peroxide are reacted as shown in Reaction Scheme 9 below to prepare dichloric acid.

<Scheme 9>

2NaClO ₃ + H ₂ SO ₄ + H ₂ O ₂ → 2ClO ₂ + 3Na ₂ SO ₄ + 2H ₂ O + O ₂

Alternatively, as a method for producing chlorine dioxide, chlorine is oxidized using chlorine (sodium chlorite) as shown in Reaction Scheme 10 to prepare dichloric acid.

<Reaction Scheme 10>

2NaClO ₂ + Cl ₂ → 2ClO ₂ + 2NaCl

This method has the disadvantage of handling chlorine gas, which is a toxic gas, but provides a high yield and has little by-products.

As a chlorine dioxide production apparatus according to Reaction Scheme 10, for example, a pH meter for monitoring the pH of the reaction solution, a chlorine dioxide outlet installed at a position symmetric to the pH meter, and a flow meter installed separately at an inlet of chlorine gas (Cl ₂ ), The chlorine gas (Cl ₂ ) inlet and chlorite (NaClO ₂ ) inlet installed symmetrically on the lower part of the reactor, the metering pump to control the supply of chlorite (NaClO ₂ ), the fine installed in the chlorine gas (Cl ₂ ) supply pipe A glass fiber membrane, chlorine dioxide (Cl ₂ ) and chlorite (NaClO ₂ ) inlet and a vertically installed baffle and a chlorine dioxide manufacturing apparatus equipped with a stirrer at the bottom center of the reactor are disclosed in Korean Patent Registration No. 10-0376913 .

In the method for producing chlorine dioxide by reacting chlorine dioxide or a mixture of chlorite or a mixture of chlorite and hypochlorite, chlorine gas and a high-pressure nozzle, a method for producing chlorine dioxide, injecting chlorite before the jet reaches the booster A method for preparing chlorine dioxide suitable for a water purification plant by using alkalinized injection water injected into water as an ejector injection solution is disclosed in Korean Patent Registration No. 10-0456483.

As a method for preparing chlorine dioxide according to Reaction Scheme 9, chlorine ions, acids and hydrogen peroxide are supplied to the reactor as an aqueous solution to reduce chlorine ions into chlorine dioxide in the reactor, and this is mixed with pressure water to dilute an aqueous solution containing chlorine dioxide. A method for continuously producing chlorine dioxide comprising the step of recovering from an ejector is disclosed in Korean Patent Registration No. 10-0590345.

As a device for generating a small amount of chlorine dioxide in a sustained release form, a sand layer or a silica gel layer / chlorine dioxide production reaction layer / king sand layer / silica gel layer or zeolite layer is sequentially filled from the bottom to the top, and a chlorine dioxide gas outlet is provided in the upper layer. It is provided, and the bottom of the device is disclosed in Korean Patent Registration No. 10-0364235 a sustained-release trace amount of chlorine dioxide having a plurality of solution absorption ports.

As a device for instantaneous generation of chlorine dioxide, a sand layer and a chlorine dioxide production reaction layer are sequentially filled from bottom to top in the tube, and a plurality of solution absorption ports are provided at the bottom of the tube to absorb the solution. A device for instantaneous generation of chlorine dioxide provided with a large number of pores through which chlorine dioxide gas is discharged is disclosed in Korean Patent Registration No. 10-0454547.

As a device for generating chlorine dioxide using ultrasonic waves and ultraviolet rays, a chlorine dioxide generating device that exposes a chlorine dioxide generating solution to ultraviolet rays with the provision of an ultrasonic vibration device to generate necessary chlorine dioxide is disclosed in Korean Patent Publication No. 2005-0015949.

In addition, as an apparatus for generating chlorine dioxide by an electrolysis method, an electric current is passed between an anode and a cathode to electrolyze an aqueous feed solution and convert a halogen dioxide salt into halogen dioxide, while the aqueous feed solution containing chlorite is added to the anode and cathode. A method for preparing chlorine dioxide by passing it in a non-membrane electrolytic cell comprising and near the anode is disclosed in Korean Patent Registration No. 10-0575036.

For example, in the step of preparing the first solution, the first solution may be prepared by mixing chlorite, hypochlorite, and inorganic acid. Specifically, the chlorite may be sodium chlorite, the hypochlorite may be sodium hypochlorite, and the inorganic acid may be sulfuric acid. In this case, a first solution containing chlorine dioxide is prepared as shown in Reaction Scheme 11 below. Since 1 equivalent of sodium chloride is generated in Reaction Scheme 11, the action of chlorine ions of sodium chloride to decompose chlorine dioxide can be minimized.

<Scheme 11>

2NaClO ₂ + NaClO + H ₂ SO ₄ → 2ClO ₂ + NaCl + Na ₂ SO ₄ + H ₂ O

On the other hand, when using hydrochloric acid as in the following Reaction Scheme 8, since 3 equivalents of sodium chloride are generated, the action of chlorine ions of sodium chloride to decompose chlorine dioxide may increase. As a result, maintaining long-term concentrations of chlorine dioxide can be difficult.

<Scheme 8>

2NaClO ₂ + NaClO + 2HCl → 2ClO ₂ + 3NaCl + H ₂ O

Then, a long-term concentration maintaining agent is added to the prepared first solution. Long-term concentration maintenance agents include chlorine dioxide inhibitors and pH adjusting agents. For example, the long-term concentration maintenance agent may further include hypochlorous acid.

For example, in 1 L of the first solution having a dissolved chlorine dioxide concentration of 1.0 to 2,000 ppm, 0.5 to 10 g of sodium chlorate in a solid state as a long-term concentration maintaining agent, or 1.0 to 5.0 g; 0.5 to 10 g of sodium chlorite in a solid state (80% purity), or 1 to 40 g of 1.0 to 5.0 g or liquid sodium chlorite (concentration 23 to 25% aqueous solution), or 2 to 20 g; Sodium hypochlorite aqueous solution (10%, weight / weight) 1.0-20.0 g, or 5.0-10.0 g; And a NaH ₂ PO ₄ solution having a concentration of 5 to 10% as a pH adjusting agent or a mixed solution consisting of two types of NaH ₂ PO _4, Na ₂ HPO ₄ (concentration 1 to 10% NaH ₂ PO ₄ and concentration 2.5 to 7.5% Na ₂ HPO ₄ ) by adding 10 ~ 200mL or 20 ~ 80mL to prepare a second solution, and stirred at room temperature for 10 minutes to prepare a long-term concentration maintaining chlorine dioxide aqueous solution composition.

The present invention is described in more detail through the following examples and comparative examples. However, the examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

(Preparation of long-term concentration maintenance chlorine dioxide aqueous solution composition)

Example 1

Sodium chlorite, sodium hypochlorite and hydrochloric acid were mixed to prepare an aqueous solution of chlorine dioxide containing 2,000 ppm of dissolved chlorine dioxide produced according to the following Reaction Scheme 8.

<Scheme 8>

2NaClO ₂ + NaClO + 2HCl → 2ClO ₂ + 3NaCl + H ₂ O

2 g of sodium chlorate, 2 g of sodium chlorite (80% purity), and 10 g of sodium hypochlorite solution (10%, weight / weight) were added to 1 L of a 2000 ppm aqueous chlorine dioxide solution.

Subsequently, 60 ml of a mixed solution of sodium dihydrogen phosphate and sodium monohydrogen phosphate (5% NaH ₂ PO _4, 5% Na ₂ HPO ₄ , weight / weight) was added to adjust the pH of the aqueous solution to 2 to 6.5 to maintain long-term concentration. An aqueous chlorine dioxide aqueous solution composition was prepared.

Example 2

Sodium chlorite, sodium hypochlorite, and hydrochloric acid were mixed to prepare an aqueous solution of chlorine dioxide containing 80 ppm of dissolved chlorine dioxide produced according to Reaction Scheme 4.

To 1 L of the prepared 80 ppm aqueous chlorine dioxide solution, 0.5 g of sodium chlorate, 0.5 g of sodium chlorite (80% purity), and 5 g of sodium hypochlorite aqueous solution (10%, weight / weight) were added to prepare a long-term concentration chlorine dioxide aqueous solution composition Did.

Subsequently, 30 ml of a mixed solution of sodium dihydrogen phosphate and sodium monohydrogen phosphate (5% NaH ₂ PO _4, 5% Na ₂ HPO ₄ , weight / weight) is added to adjust the pH of the aqueous solution to 2 to 6.5 to maintain long-term concentration. An aqueous chlorine dioxide aqueous solution composition was prepared.

Example 3

Sodium chlorite, sodium hypochlorite and hydrochloric acid were mixed to prepare an aqueous solution of chlorine dioxide containing 20 ppm of dissolved chlorine dioxide produced according to Reaction Scheme 4.

Sodium chlorate 0.0.1 g, sodium chlorite (purity 80%) 0.0.1 g, and sodium hypochlorite aqueous solution (10%, weight / weight) 2 g were added to 1 L of the prepared 20 ppm aqueous chlorine dioxide solution to maintain long-term concentration. Was prepared.

Subsequently, 20 ml of a mixed solution of sodium dihydrogen phosphate and sodium monohydrogen phosphate (5% NaH ₂ PO _4, 5% Na ₂ HPO ₄ , weight / weight) was added to adjust the pH of the aqueous solution to 2 to 6.5 to maintain long-term concentration. An aqueous chlorine dioxide aqueous solution composition was prepared.

Comparative Example 1

This comparative example was exemplified for the purpose of measuring the degree of long-term concentration maintenance when only sodium chlorite and pH adjusters were used without adding sodium chlorate and sodium hypochlorite as decomposition inhibitors.

Sodium chlorite, sodium hypochlorite and hydrochloric acid were mixed to prepare an aqueous solution of chlorine dioxide containing 2,000 ppm of dissolved chlorine dioxide produced according to the following Reaction Scheme 8.

<Scheme 8>

2NaClO ₂ + NaClO + 2HCl → 2ClO ₂ + 3NaCl + H ₂ O

PH of the aqueous solution obtained by adding 80 mL of sodium chlorite (25% solution) to 1 L of a 2000 ppm aqueous chlorine dioxide solution, and then adding sodium dihydrogen phosphate (pH of 5% aqueous solution at 25 ° C is 4.1 to 4.5) Was adjusted to 5.5 to 6.0 to prepare a chlorine dioxide aqueous solution composition.

Evaluation Example 1: Evaluation of dissolved chlorine dioxide at room temperature stability

The long-term concentration-maintaining chlorine dioxide aqueous solution compositions prepared in Examples 1 to 3 were stored at room temperature (25 ° C.) for a long time, and the chlorine dioxide content contained in the long-term concentration-maintaining chlorine dioxide aqueous solution composition was measured at an interval of 1 month by an iodine titration method.

The measurement results are shown in Table 1 below.

Elapsed time Example 1 Example 2 Example 3 Comparative Example 1 Early 2000 80. 20.0 2000 1 month 2003 80.4 20.7 839 2 months 2001 80.3 21.1 624 3 months 1997 79.1 21.2 610 4 months 2000 80.3 20.5 589 5 months 1999 81.1 20.1 578 6 months 2002 80.9 19.9 499 7 months 2001 80.6 19.4 8 months 2000 79.7 20.2 9 months 2003 80.1 20.2 10 months 2001 79.9 20.7 11 months 2000 80.6 20.1 12 months 2003 80.6 19.9 13 months 2001 79.4 20.2

As shown in Table 1, in the long-term concentration chlorine dioxide aqueous solutions prepared in Examples 1 to 3, the content of residual chlorine dioxide after 12 months was 94% or more of the initial chlorine dioxide content, but the organs prepared in Comparative Example 1 Concentration maintenance In the aqueous chlorine dioxide solution, the residual chlorine dioxide content after 6 months was less than 25% of the initial chlorine dioxide content.

Therefore, the long-term concentration-maintained chlorine dioxide aqueous solutions prepared in Examples 1 to 3 were excellent in long-term storage stability at room temperature.

On the other hand, the long-term concentration-maintaining chlorine dioxide aqueous solution prepared in Comparative Example 1 lacked sodium chloride and sodium hypochlorite as decomposition inhibitors, resulting in poor long-term storage stability at room temperature.

Claims (22)

Dissolved chlorine dioxide;
An inhibitor of decomposition of the dissolved chlorine dioxide; And
A long-term concentration maintenance chlorine dioxide aqueous solution composition comprising a pH adjusting agent,
The decomposition inhibitors include sodium chlorite, sodium hypochlorite and sodium chlorate,
The pH adjusting agent includes sodium dihydrogen phosphate and sodium monohydrogen phosphate,
The initial content of sodium chlorate and sodium chlorite is 0.36% by weight or less based on the total weight of the aqueous chlorine dioxide solution, and the initial content of sodium hypochlorite is 0.1% by weight or less based on the total weight of the aqueous chlorine dioxide solution,
The dissolved chlorine dioxide concentration is 2000ppm or less, characterized in that the long-term concentration maintained at room temperature, chlorine dioxide aqueous solution composition. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete Preparing a first solution containing dissolved chlorine dioxide; And
And adding a long-term concentration maintaining agent including a decomposition inhibitor of chlorine dioxide and a pH adjusting agent to the first solution,
The decomposition inhibitors include sodium chlorite, sodium hypochlorite and sodium chlorate,
The pH adjusting agent includes sodium dihydrogen phosphate and sodium monohydrogen phosphate,
The initial content of the decomposition inhibitors sodium chlorate and sodium chlorite is 0.36% by weight or less based on the total weight of the aqueous chlorine dioxide solution, and the initial content of sodium hypochlorite is 0.1% by weight or less based on the total weight of the aqueous chlorine dioxide solution,
The dissolved chlorine dioxide concentration is 2000ppm or less, characterized in that the long-term long-term concentration maintaining chlorine dioxide aqueous solution composition. delete delete delete