Method for producing chlorous acid water by chlorine dioxide adsorption

Abstract

To provide a novel method for producing chlorous acid water that can stably maintain chlorous acid in water for extended periods. [Solution] A method for maintaining chlorous acid (HClO2) stably in water for a long period of time by trapping (capturing or adsorbing) chlorine dioxide gas (ClO2) with an inorganic acid, inorganic acid salt, organic acid, or organic acid salt, either individually or in combination with two or more of these, thereby creating a transition state and slowing down the decomposition reaction. For example, a gas cleaning device 2 is filled with H2O, NaOH, and H2O2 as a gas cleaning liquid, chlorine dioxide gas is prepared in a chlorine dioxide gas storage tank 3, sodium carbonate, dipotassium hydrogen phosphate, and sodium tetraborate are filled in a chlorous acid water production tank 1, and an air pump 4 is operated to introduce chlorine dichloride into the chlorous acid water production tank 1 to produce chlorous acid water.

Description

[Technical Field]

[0001] This invention relates to a method for producing chlorous acid water by chlorine dioxide adsorption. [Background technology]

[0002] Chlorous acid water is attracting attention as a food additive. However, it is difficult to manufacture, and even if it can be produced, it has the problem of not being able to be stored under normal conditions.

[0003] On the other hand, the inventor has found a method for producing chlorous acid water and has also confirmed its bactericidal effect against E. coli before filing the patent application (Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2008 / 026607 [Overview of the project] [Means for solving the problem]

[0005] This invention discovers and provides a novel method for producing chlorous acid water.

[0006] In one aspect, the present invention provides a method for maintaining chlorous acid (HClO2) stably in water for a long period of time by trapping (capturing or adsorbing) chlorine dioxide gas (ClO2) with an inorganic acid, inorganic acid salt, organic acid, or organic acid salt, either individually or in combination with two or more of these, thereby creating a transition state and delaying the decomposition reaction. In preferred embodiments of these methods, the addition of an inorganic acid, inorganic acid salt, organic acid, or organic acid salt, either individually or in combination with two or more of these, to the aqueous solution can be utilized.

[0007] Examples of the inorganic acids mentioned above include carbonic acid, phosphoric acid, boric acid, or sulfuric acid. Examples of inorganic salts include carbonates, hydroxides, phosphates, or borates. More specifically, suitable carbonates include sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, etc.; hydroxides include sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, etc.; phosphates include disodium hydrogen phosphate, sodium dihydrogen phosphate, trisodium phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, dipotassium phosphate, etc.; and borates include sodium borate, potassium borate, etc. Examples of the organic acids mentioned above include succinic acid, citric acid, malic acid, acetic acid, or lactic acid. Suitable organic salts include sodium succinate, potassium succinate, sodium citrate, potassium citrate, sodium malate, potassium malate, sodium acetate, potassium acetate, sodium lactate, potassium lactate, or calcium lactate.

[0008] This invention also provides the following: (1) A method for producing chlorous acid water, comprising the step of adsorbing (trapping) chlorine dioxide (ClO2) onto an aqueous solution A containing one or more inorganic acids, inorganic acid salts, organic acids, or organic acid salts, or a combination thereof. (2) The method according to item 1, further comprising the step of adding chlorine dioxide in the presence of hydrogen peroxide. (3) The method according to item 1 or 2, wherein the pH of the aqueous solution A is 11.0 or less and 6.0 or more. (4) The method according to any one of items 1 to 3, wherein the pH of the aqueous solution A is 10.8 or less and 10.2 or more. (5) The TAL of aqueous solution A is 20 to 2000, where TAL is determined by the titration volume of 0.1N-HCl from an initial pH of 11.0 or less to pH 4, according to any of the methods in items 1 to 4. Here, TAL is the TAL of the aqueous solution before blowing in chlorine dioxide gas, and the aqueous solution produced after blowing in is chlorous acid water. At this time, the TAL of the aqueous solution decreases compared to aqueous solution A. By adding a specific buffer (aqueous solution B) as specified in the present invention to this aqueous solution, the chlorous acid and chlorite ions are stabilized. The reason for keeping the initial pH of aqueous solution A low and limiting the range of TAL is to eliminate the strong alkaline buffering capacity unique to sodium hydroxide, and then limit the solution to one that has buffering capacity in the weakly acidic to weakly alkaline range. (6) The method according to any one of items 1 to 5, wherein the chlorine dioxide (ClO2) is provided as a gas. (7) The method according to any one of items 1 to 6, further comprising the step of adding an aqueous solution B containing one or more inorganic acids, inorganic acid salts, organic acids, or organic acid salts, or a combination thereof, after the above-mentioned adding step. (8) The method according to any one of items 1 to 7, wherein the inorganic acid is carbonic acid, phosphoric acid, boric acid, or sulfuric acid. (9) The method according to any one of items 1 to 8, wherein the inorganic salt is a carbonate, hydroxide, phosphate, or borate. (10) The method according to item 9, wherein the carbonate is sodium carbonate, potassium carbonate, sodium bicarbonate, or potassium bicarbonate. (11) The method according to item 9, wherein the hydroxide salt is sodium hydroxide, potassium hydroxide, calcium hydroxide or barium hydroxide. (12) The method according to item 9, wherein the phosphate is disodium hydrogen phosphate, sodium dihydrogen phosphate, trisodium phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, or potassium dihydrogen phosphate. (13) The method according to item 9, wherein the borate is sodium borate or potassium borate. (14) The method according to any one of items 1 to 13, wherein the organic acid salt is succinic acid, citric acid, malic acid, acetic acid, or lactic acid. (15) The method according to any one of items 1 to 14, wherein the organic acid salt is sodium succinate, potassium succinate, sodium citrate, potassium citrate, sodium malate, potassium malate, sodium acetate, potassium acetate, sodium lactate, potassium lactate, or calcium lactate. (16) The method according to any of items 4 to 15, wherein the pH of the solution after adding aqueous solution B is 3.2 or more and less than 7.0. (17) The method according to any of items 4 to 16, wherein the pH of the solution after adding aqueous solution B is 4.0 or more and less than 7.0. (18) The method according to any of items 4 to 17, wherein the pH of the solution after adding aqueous solution B is 5.0 or more and less than 7.0. (19) The chlorine dioxide gas is present in a concentration of 0.8 to 1.0% as described in any of items 1 to 18. (20) Chlorous acid water produced by a method that includes a step of trapping chlorine dioxide (ClO2) in an aqueous solution A containing one or more inorganic acids, inorganic acid salts, organic acids, or organic acid salts, or a combination thereof. (21) The chlorous acid water described in item 20, wherein the method further comprises the step of adding chlorine dioxide in the presence of hydrogen peroxide. (22) The pH of the aqueous solution A is 11.0 or less and 6.0 or more, as described in item 20 or 21. Chloric acid water. (23) The pH of aqueous solution A is 10.8 or less and 10.2 or greater, as indicated in any of items 20 to 22. The included chlorous acid water. (24) Chlorous acid water according to any of items 20 to 23, wherein the chlorine dioxide (ClO2) is provided as a gas.

[0009] Further embodiments and advantages of the present invention will be apparent to those skilled in the art, who may read and understand the detailed description below as needed. [Effects of the Invention]

[0010] According to the present invention, a technique for stabilizing chlorous acid, which is a useful substance, in an aqueous solution for a long period of time is provided. As chlorous acid water that is convenient to handle, there is a high possibility that it can be widely used not only in the food industry but also in many fields such as welfare and nursing facilities, and further in medical facilities and the like.

Brief Description of the Drawings

[0011] [Figure 1] Figure 1 shows a schematic diagram of the production plant used in the examples. Each reference numeral is as follows. 1: Chlorous acid water production tank, 2: Gas washing device, 3: Chlorine dioxide gas storage tank, 4: Air pump, 5: Air inlet cock. [Figure 2] Shows the UV spectrum in Example 1. A doublet is observed. [Figure 3] Shows the UV spectrum in Example 2. A doublet is observed. [Figure 4] Shows the UV spectrum in Example 3. A doublet is observed. [Figure 5] Shows the UV spectrum in Example 4. A doublet is observed. [Figure 6] Shows the UV spectrum in Example 5. A doublet is observed. [Figure 7] Shows the UV spectrum in Example 6. A doublet is observed. [Figure 8] Figure 8 shows a comparison of the stability of the chlorous acid water preparations produced in Example 2 and Example 4 performed in Example 7 with the control. The horizontal axis represents the number of days, and the vertical axis represents the chlorous acid concentration.

Modes for Carrying Out the Invention

[0012] The present invention is described below. Throughout this specification, singular expressions should be understood to include the concept of their plural form unless otherwise specified. Accordingly, singular articles (for example, "a," "an," and "the" in English) should be understood to include the concept of their plural form unless otherwise specified. Furthermore, terms used herein should be understood to have the meaning commonly used in the art unless otherwise specified. Accordingly, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. In case of any conflict, this specification (including definitions) shall prevail. In this specification, "chlorous acid water" refers to an aqueous solution containing chlorous acid (HClO2) used as a disinfectant. The chlorous acid water of the present invention can maintain chlorous acid (HClO2) stably for a long period of time by creating a transition state and delaying the decomposition reaction. When a sample of chlorous acid water is measured with a spectrophotometer, the acidic chlorite ion (H) shows a peak around 260 nm between wavelengths of 240 to 420 nm in the UV spectrum. + +ClO2 - When two absorption regions are simultaneously observed, one containing chlorine dioxide (ClO2) and the other showing a peak around 350 nm, i.e., when a double nodule is observed, the presence of chlorous acid water can be detected. In this case, the main component is chlorous acid (HClO2), with chlorine dioxide (ClO2) and acidic chlorite ions (H2O2). + +ClO2 - We assume that the following cyclical reactions are occurring simultaneously.

[0013] In this specification, the term "chlorous acid water" may encompass "chlorous acid water preparation." A chlorous acid water preparation can be produced by combining aqueous solution B with chlorous acid water produced by the method of the present invention. A typical composition of the chlorous acid water preparation is, but is not limited to, 60.00% (w / v) chlorous acid water (5%) (the concentration of chlorous acid is 5000%). It is 0 ppm. ), potassium dihydrogen phosphate 1.70% (w / v), potassium hydroxide 0.5 A mixture of 0% (w / v) and 37.8% (w / v) purified water can be used (sold by the applicant under the name "Outulock Super"). However, in this formulation, the concentrations of chlorous acid water are 0.25% (w / v) to 75% (w / v), potassium dihydrogen phosphate is 0.70% (w / v) to 13.90% (w / v), and potassium hydroxide is 0.10% (w / v) to... 5.60% (w / v) is also acceptable. Sodium dihydrogen phosphate can be used instead of potassium dihydrogen phosphate. You can use sodium hydroxide instead of potassium hydroxide for the lium.

[0014] In this specification, "stable" in chlorous acid water refers to a state in which chlorous acid (HClO2) is maintained.

[0015] In this specification, "antibacterial (action)" refers to the suppression of growth of microorganisms such as filamentous fungi, bacteria, and viruses that are pathogenic, harmful, or infectious. Substances that have antibacterial action are called antibacterial agents.

[0016] In this specification, "bactericidal action" refers to the killing of microorganisms such as filamentous fungi, bacteria, and viruses that are pathogenic, harmful, or infectious. Substances that have a bactericidal action are called bactericides.

[0017] In this specification, "disinfection (action)" refers to the removal of microorganisms such as filamentous fungi, bacteria, and viruses that are pathogenic, harmful, or infectious. Substances that have a disinfecting action are called disinfectants.

[0018] In this specification, "disinfection (action)" refers to the disinfection of microorganisms such as filamentous fungi, bacteria, and viruses that are pathogenic, harmful, or infectious. Substances that have a disinfecting action are called disinfectants.

[0019] Antibacterial, bactericidal, germicidal, and disinfectant actions are collectively referred to as "killing (action)," and unless otherwise specified in this specification, this broad concept includes antibacterial, bactericidal, germicidal, and disinfectant actions. Therefore, substances that have antibacterial, bactericidal, germicidal, or disinfectant actions are collectively referred to as "bactericides" in this specification, and when used in this specification, they are understood to be agents that also possess antibacterial, bactericidal, germicidal, or disinfectant actions.

[0020] In this specification, articles used with the manufactured chlorous acid water are any articles that can be impregnated with chlorous acid water and used for sterilization or other purposes, and include medical devices, but are not limited to, sheets, films, patches, brushes, nonwoven fabrics, paper, cloth, absorbent cotton, sponges, etc. Furthermore, any material can be used as long as it can be impregnated with chlorous acid water.

[0021] In this specification, "TAL" refers to the alkalinity of a sample, defined as 1 when 1 mL of 0.1 mol / L hydrochloric acid is needed to bring the pH of 100 g of sample to 4.0 by titrating the sample with 0.1 mol / L hydrochloric acid-acid standard solution until the pH reaches 4.0. pH 4.0 is the second neutralization point of sodium carbonate.

[0022] (Chlorous acid water and its manufacturing examples) The chlorous acid water used in this invention has characteristics and functions discovered by the inventors.

[0023] The present invention relates to a method different from known manufacturing methods, such as those described in Patent Document 1.

[0024] In other words, the features of the present invention are achieved by providing a method for producing chlorous acid, which involves adding chlorine dioxide gas (ClO2) to an inorganic acid, inorganic acid salt, organic acid, or organic acid salt, either individually or in combination (Aqueous Solution A), instead of adding hydrogen peroxide to chloric acid. Conventionally, a sodium chlorate aqueous solution is reacted with sulfuric acid or an aqueous solution in an amount and concentration that can maintain the pH of the aqueous solution between 2.3 and 3.4 to generate chloric acid, and then an amount equal to or greater than the amount of hydrogen peroxide required for the reduction reaction of the chloric acid is added. By using chlorine dioxide gas (gas) as a raw material, chlorite ions are generated with high alkalinity, and at that time the pH drops to neutral or below. As a result, some of the chlorite ions transition to the chlorous acid state, creating a transition state, and as a result the decomposition reaction is delayed, allowing for the stable maintenance of chlorous acid (HClO2) over a long period of time. This effect is achieved by trapping chlorine dioxide (ClO2) in an aqueous solution A containing one or more inorganic acids, inorganic acid salts, organic acids, or organic acid salts, or a combination thereof. The term "trap" refers to any operation, preferably such as adsorption or capture, that results in gaseous chlorine dioxide coexisting with one or more inorganic acids, inorganic acid salts, organic acids, or organic acid salts, or a combination thereof. Such operations generally include, but are not limited to, methods such as directly blowing into aqueous solution A, or adsorption by spraying aqueous solution A from above in a mist and releasing chlorine dioxide gas from below, or spraying. Although we do not wish to be bound by theory, the chlorous acid water of the present invention (see Examples 1-6) produced using a manufacturing plant as shown in Figure 1 has been proven to exhibit a stable bactericidal effect for at least 10 days at refrigeration (4°C), as shown in Example 7, and it is understood that the present invention provides a method for producing chlorous acid water in which chlorous acid is stable in an aqueous solution.

[0025] A chlorous acid solution preparation can be manufactured by combining aqueous solution B with the chlorous acid solution produced by the manufacturing method of the present invention. A typical composition of such a preparation is, but is not limited to, 60.00% (w / v) (chlorous acid solution (5%)). The concentration of nitrate is 50,000 ppm. The mixture consists of 1.70% (w / v) potassium dihydrogen phosphate, 0.50% (w / v) potassium hydroxide, and 37.8% (w / v) purified water. It can be used. (It is sold by the applicant under the name "Outulock Super".) Moreover, in the case of this formulation, the chlorous acid water is 0.25% (w / v) ~ 75 %(w / v), potassium dihydrogen phosphate is 0.70%(w / v)~13.90%(w / v), hydroxyl Potassium dihydrogen may be present in concentrations of 0.10% (w / v) to 5.60% (w / v). Sodium dihydrogen phosphate may be used instead of potassium dihydrogen phosphate, and sodium hydroxide instead of potassium hydroxide. This agent reduces the attenuation of chlorous acid due to contact with organic matter under acidic conditions, while maintaining its bactericidal effect. Furthermore, it has the characteristics of producing only minimal chlorine gas and suppressing the amplification of chlorine odor generated when chlorine reacts with organic matter.

[0026] In conventional methods, chlorous acid water was produced by reacting an aqueous solution of sodium chlorate with sulfuric acid or an aqueous solution thereof in an amount and concentration that maintains the pH of the aqueous solution at 3.4 or below to generate chloric acid, and then adding an amount of hydrogen peroxide equal to or greater than the amount required for the reduction reaction of the chloric acid. The present invention differs significantly in that it uses chlorine dioxide gas, and by creating a transition state and delaying the decomposition reaction, it is possible to stably maintain chlorous acid (HClO2) for a long period of time. In addition, by using chlorine dioxide as a raw material, there is no need to specify a raw material for generating chlorine dioxide gas. For example, when acid is added to sodium chlorite, chlorine dioxide gas is generated in addition to acidified sodium chlorite (ASC). However, this chlorine dioxide Chlorous acid water can be produced using gas. Sodium chlorite is a highly alkaline substance that is stable when integrated with alkaline substances, and to be effective as a disinfectant, it must be in the form of acidified sodium chlorite (ASC). However, by using this method, it is possible to produce liquid chlorous acid water by using gaseous chlorine dioxide, which is generated separately from the liquid acidified sodium chlorite, as a raw material. Furthermore, when producing chlorous acid water from table salt, there is a process of electrolysis, which causes bromide ions in the table salt to change into bromate, a carcinogenic substance, and there was a risk that the bromate generated at this time would be mixed into the chlorous acid water. However, by using the manufacturing method of the present invention, since gaseous chlorine dioxide gas is used, the risk of such carcinogenic substances being mixed in is eliminated. Another feature is that by using chlorine dioxide gas as a raw material, it becomes unnecessary to consider the preceding processes, making it easier to produce chlorous acid water. In addition, in the method of producing chlorous acid water from sodium chlorite, the generation of chlorine dioxide gas is undesirable, so it is desirable to increase the alkalinity, and it was considered preferable for the pH to be as close to 14 as possible. Therefore, the present method of producing chlorous acid water using aqueous solution A with a pH of 6.0 to 11.0 as shown in the present invention is the exact opposite of the method of producing chlorous acid water from sodium chlorite. It can be said that this was done in the manufacturing process of sodium phosphate.

[0027] In one embodiment, the chlorine dioxide gas (ClO2) is provided as a gas. In a specific embodiment, the chlorine dioxide gas (ClO2) is a gas and is used at a concentration of 0.8 to 1.0% (for example, the permissible range is 0.9% ± 0.1%). One preferred concentration is 0.88%, but it is not limited to this. High concentrations are explosive and therefore dangerous, and should be diluted with nitrogen gas or the like before use.

[0028] In one embodiment, the chlorine dioxide gas is added in the presence of hydrogen peroxide (H2O2). In another embodiment, the aqueous solution A may contain hydrogen peroxide, and the chlorine dioxide gas is trapped in the aqueous solution A containing hydrogen peroxide. By allowing the chlorine dioxide gas to coexist with hydrogen peroxide (H2O2), the generation of chlorate ions is suppressed, and chlorite ions, chlorous acid, and aqueous chlorine dioxide are simultaneously present in a so-called "cycle reaction" to produce chlorous acid (HClO2).

[0029] In a preferred embodiment, the addition step includes further adding one or more inorganic acids, inorganic acid salts, organic acids, or organic acid salts, or a combination thereof. This is because the pH and other parameters can be adjusted by adding these further steps to control the transition state.

[0030] In another embodiment, the inorganic acid used in the above method may be carbonic acid, phosphoric acid, boric acid, or sulfuric acid, but phosphoric acid is preferred. While we do not wish to be bound by theory, the present invention has shown that using phosphoric acid in particular allows for a high buffering effect within an appropriate pH range, maintaining the chlorite state while preserving the bactericidal effect.

[0031] Furthermore, in another embodiment, the inorganic acid salt may be a carbonate, hydroxide, phosphate, or borate, with phosphate being preferred. While we do not wish to be bound by theory, the present invention has shown that the use of phosphate in particular allows for a high buffering effect within an appropriate pH range, maintaining the chlorite state while preserving the bactericidal effect.

[0032] In another embodiment, sodium carbonate, potassium carbonate, sodium bicarbonate, or potassium bicarbonate can be used as the carbonate. Sodium carbonate is preferred because it has buffering capacity in both the weakly alkaline and weakly acidic pH ranges, allowing for more advantageous stabilization of chlorous acid in these ranges.

[0033] Furthermore, in another embodiment, sodium hydroxide, potassium hydroxide, calcium hydroxide, or barium hydroxide can be used as the hydroxide. Potassium hydroxide or sodium hydroxide is preferred. Although we do not wish to be bound by theory, these hydroxides can be used to increase the chlorite content. On the other hand, using a divalent salt in combination with phosphoric acid may be advantageous because it can be desalted, thereby reducing the amount of salt relative to chlorite and chlorite ions.

[0034] Furthermore, in another embodiment, disodium hydrogen phosphate, dihydrogen dihydrogen phosphate, trisodium phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, or potassium dihydrogen phosphate can be used as the phosphate. Preferably, dipotassium hydrogen phosphate can be used. Although we do not wish to be bound by theory, this is because these phosphates can provide buffering capacity in the useful pH range of pH 5 to pH 6, which is where they exert the most bactericidal effect. This may be advantageous because it allows chlorite to be stably present in this pH range.

[0035] In another embodiment, sodium borate or potassium borate can be used as the borate.

[0036] Furthermore, in another embodiment, succinic acid, citric acid, malic acid, acetic acid, or lactic acid can be used as the organic acid. Preferably, succinic acid can be used. Although we do not wish to be bound by theory, succinic acid can provide buffering capacity between pH 5 and pH 4. Within this pH range, the rapid gasification of chlorine dioxide can be suppressed. However, below pH 5, the pH tends to drop rapidly, and in that case, it is desirable to use an organic acid that has buffering capacity at pH 3, such as citric acid.

[0037] Furthermore, in another embodiment, the organic acid salts that can be used are sodium succinate, potassium succinate, sodium citrate, potassium citrate, sodium malate, potassium malate, sodium acetate, potassium acetate, sodium lactate, potassium lactate, or calcium lactate.

[0038] In one embodiment, the initial pH of the buffering agent into which chlorine dioxide is blown is typically 11.0 or less and 6.0 or more, more preferably 10.8 or less and 10.2 or more, but is not limited thereto. When the initial pH is 10.8 or less and 10.2 or more, the formation of chlorite is suppressed, the final effective chlorine concentration is increased, and the yield is improved. In this specification, pH values ​​are rounded to one significant figure. For example, if the measured value is pH 10.83, it is shown as pH 10.8.

[0039] Ideally, this pH could be 11.0 or higher, which would increase the final effective chlorine concentration and improve the yield. However, using sodium hydroxide (caustic soda), etc., would generate sodium chlorite, which contradicts the objective of the present invention and is therefore undesirable. While we do not wish to be bound by theory, when producing sodium chlorite, chlorine dioxide gas is adsorbed into an aqueous solution of high-concentration sodium hydroxide with hydrogen peroxide. The pH of the aqueous solution before adsorption to chlorine dioxide gas is strongly alkaline, at pH 11.3 or higher, and in reality, it is pH 12 or higher. Furthermore, the recovery rate is close to 100%. Therefore, only one adsorption tank is needed (normally, two or more adsorption tanks are required because the recovery rate of chlorous acid water is low), and the product in this case is sodium chlorite, not chlorous acid water. Therefore, the pH suitable for the purpose of this invention is any condition under which chlorine dioxide gas can be contained. For example, a typical pH range is 6.0 to 11.0, preferably 10.2 to 10.8, but it is not limited to this range. Examples of preferred pH ranges include, as upper limits, 11.2, 11.1, 11.0, 10.9, 10.8, and 10.9. Possible upper limits for pH include, but are not limited to, values ​​such as 0.7, 10.6, 10.5, 10.4, 10.3, 10.2, 10.1, 10.0, 9.9, 9.8, 9.7, 9.6, 9.5, 9.4, 9.3, 9.2, 9.1, and 9.0. Preferred upper limits for pH include values ​​less than 11, less than 10.5, less than 10, less than 9.5, less than 9, less than 8.5, less than 8, less than 7.5, less than 7, and less than 6.5. Preferred lower limits for pH include 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0, 10.1, 10.2, etc., but are not limited to these. Preferred lower limits for pH include values ​​greater than 6, greater than 6.5, greater than 7, greater than 7.5, greater than 8, greater than 8.5, greater than 9, greater than 9.5, greater than 10, etc. Any combination of these upper and lower limits may be appropriate and can be used in the present invention. Preferred combinations of upper and lower limits include 6.0 to 6.5, 6.0 to less than 6.5, 6.0 to 9.0, 6.0 to less than 9.0, 6.0 to 10.0, 6.0 to less than 10.0, 6.0 to 11.0, 6.0 to less than 11.0, greater than 6.0 to 6.5, greater than 6.0 to 9.0, greater than 6.0 to 10.0, greater than 6.0 to 11.0, greater than 6.0 to less than 6.5, and 6.0 Examples include values ​​greater than 6.0 but less than 9.0, values ​​greater than 6.0 but less than 10.0, values ​​greater than 6.0 but less than 11.0, values ​​between 7.0 and 9.0, values ​​between 7.0 and less than 9.0, values ​​between 7.0 and 10.0, values ​​between 7.0 and less than 10.0, values ​​between 7.0 and 11.0, values ​​greater than 7.0 but less than 9.0, values ​​greater than 7.0 but less than 11.0, and so on.

[0040] When chlorous acid water is produced, adsorbing chlorine dioxide gas into a low-concentration alkaline aqueous solution creates a small buffer zone between pH 6 and pH 8 (normal sodium chlorite does not have such a buffer zone). The substance in this buffer zone is chlorous acid or chlorite ions, and in order to maintain this state for a long time, a buffering agent is needed to maintain strong buffering capacity in this pH range. It is preferable to select the buffering agent and pH range to meet this condition.

[0041] While a stronger buffering capacity in the pH range of 14 to 10 allows for a higher sodium chlorite content, the manufacturing method of this invention is solely for producing an aqueous solution that maintains the cyclic reaction between chlorous acid, chlorine dioxide, and chlorite ions. Therefore, it is necessary to raise the initial pH of aqueous solution A, which is strongly alkaline to produce sodium chlorite, to pH 11.0 or higher. However, since this invention is not a method for producing sodium chlorite, it is preferable to avoid the conditions under which sodium chlorite is formed. Although we do not wish to be bound by theory, it is important for this invention to strengthen the buffering capacity in the neutral to weakly acidic range, and TAL (however, initially pH 11.0 or lower) was adopted as an indicator. If the pH of the resulting chlorous acid water is low, the pH may be raised by adding a buffering agent. In one embodiment, when a buffering agent is added using the resulting chlorous acid water, the pH range may be 3.2 to 7.0.

[0042] While there is currently no optimal concentration of chlorine dioxide gas to be injected, in one embodiment, concentrations of 0.8-1.0% can be used, and in one specific example, 0.88% can be used. Although we do not wish to be bound by theory, high concentrations are dangerous because they are explosive, and are usually diluted by introducing nitrogen gas or similar substances before use.

[0043] Production of aqueous solutions containing chlorous acid (HClO2) that can be used as disinfectants (chlorous acid water) Conventionally, the method involves adding sulfuric acid (H2SO4) or an aqueous solution of sulfuric acid to an aqueous solution of sodium chlorate (NaClO3) to create acidic conditions, and then adding the necessary amount of hydrogen peroxide (H2O2) to produce chlorous acid (HClO2) through a reduction reaction. The basic chemical reactions of this production method are represented by equations A and B below.

[0044] [C1] 2NaClO3+H2SO4→2HClO3+Na2SO4 (formula A) HClO3+H2O2→HClO2+H2O+O2↑ (B formula) Equation A shows that chloric acid is obtained and sodium ions are removed simultaneously by adding sulfuric acid (H2SO4) or an aqueous solution of it in an amount and concentration that maintains the pH value of an aqueous solution of sodium chlorate (NaClO3) within the acidic range. Next, equation B shows that chloric acid (HClO3) is reduced by hydrogen peroxide (H2O2) to produce chlorous acid (HClO2).

[0045] [ka]

[0046] During this process, chlorine dioxide gas (ClO2) is generated (Equation C), but by coexisting it with hydrogen peroxide (H2O2), it proceeds through the reactions of Equations D to F to produce chlorous acid (HClO2). This invention utilizes the reactions that occur after the generation of chlorine dioxide gas (ClO2). Although we do not wish to be bound by theory, when we isolated and utilized this reaction, we unexpectedly found that it creates a transition state, delaying the decomposition reaction and allowing us to stably maintain chlorous acid (HClO2) for a long period of time.

[0047] By the way, the generated chlorous acid (HClO2) undergoes decomposition reactions between multiple chlorous acid molecules, and also contains chloride ions (Cl -It has the property of quickly decomposing into chlorine dioxide gas or chlorine gas in the presence of chlorous acid (HClO) and other reducing agents. Therefore, in order to make it useful as a disinfectant, it is necessary to prepare it in a way that maintains the chlorous acid (HClO2) state for a long time.

[0048] Therefore, by adding an inorganic acid, inorganic acid salt, organic acid, or organic acid salt, either individually or in combination with two or more of them, to the chlorous acid (HClO2), chlorine dioxide gas (ClO2), or aqueous solution containing these obtained by the above method, a transition state can be created, delaying the decomposition reaction and allowing the chlorous acid (HClO2) to be maintained stably for a long period of time. Although we do not wish to be bound by theory, the present invention further demonstrates that, for example, by using a phosphate buffer, a transition state can be created, delaying the decomposition reaction and allowing the chlorous acid (HClO2) to be maintained stably for a long period of time. Furthermore, although we do not wish to be bound by theory, this invention has shown that using potassium salts (potassium hydroxide, potassium phosphate (e.g., tripotassium phosphate, dipotassium hydrogen phosphate, or potassium dihydrogen phosphate)) as the metal allows for a longer and more stable transition state to be created than using sodium salts (e.g., sodium hydroxide, sodium phosphate (disodium hydrogen phosphate, sodium dihydrogen phosphate, trisodium phosphate)) as the metal, and moreover, by delaying the decomposition reaction, chlorous acid (HClO2) can be maintained for a long period of time.

[0049] In one embodiment, an inorganic acid or inorganic salt, specifically a phosphate, carbonate, or hydroxide, particularly a phosphate and hydroxide, can be added to the chlorous acid (HClO2), chlorine dioxide gas (ClO2), or aqueous solution containing these obtained by the above method, either individually or in combination with two or more other types of phosphates and hydroxides.

[0050] In another embodiment, an inorganic acid or an inorganic acid salt, specifically a phosphate, carbonate or hydroxide salt, particularly phosphates and hydroxide salts, alone or in combination of two or more thereof, or an aqueous solution added with these, can be used by adding an inorganic acid, an inorganic acid salt, an organic acid or an organic acid salt alone or in combination of two or more thereof, or by using a combination thereof.

[0051] In addition, in yet another embodiment, an inorganic acid, an inorganic acid salt, an organic acid or an organic acid salt added alone or in combination of two or more thereof, or a combination thereof, can be used with respect to the aqueous solution produced by the above method.

[0052] Examples of the inorganic acid include carbonic acid, phosphoric acid, boric acid or sulfuric acid, with phosphoric acid being preferred, but not limited thereto. Examples of the inorganic acid salt include carbonates, hydroxide salts, as well as phosphates or borates, with phosphates being preferred, but not limited thereto. More specifically, examples of the carbonate include sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, etc., examples of the hydroxide salt include sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, etc., examples of the phosphate include disodium hydrogen phosphate, sodium dihydrogen phosphate, trisodium phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, etc., examples of the borate include sodium borate, potassium borate, etc., and potassium salts are preferred, but not limited thereto. Further, examples of the organic acid include succinic acid, citric acid, malic acid, acetic acid or lactic acid, etc. Examples of the organic acid salt include sodium succinate, potassium succinate, sodium citrate, potassium citrate, sodium malate, potassium malate, sodium acetate, potassium acetate, sodium lactate, potassium lactate or calcium lactate, etc.

[0053] When an acid and / or its salt is added, temporarily Na + +ClO2 - ⇔Na-ClO2 or K + +ClO2 - ⇔K-ClO2 or H + +ClO2- A transition state such as ⇔H-ClO2 is created, which can slow down the conversion of chlorous acid (HClO2) to chlorine dioxide (ClO2). This makes it possible to maintain chlorous acid (HClO2) for a long time and produce an aqueous solution containing chlorous acid with less generation of chlorine dioxide (ClO2). Although we do not wish to be bound by theory, this invention has shown that the effect of maintaining the chlorous acid is enhanced by using a phosphate buffer. Although we do not wish to be bound by theory, this invention has further shown that the effect of maintaining the chlorous acid is further enhanced by using a potassium salt compared to using a sodium salt, etc.

[0054] The following illustrates the decomposition of the chlorite salt in an acidic solution according to chemical formula 2 above.

[0055] [ka]

[0056] As shown in this equation, the decomposition rate of a chlorite solution at a given pH increases as the pH decreases, i.e., as the acidity increases. In other words, the absolute rates of reactions (a), (b), and (c) in the above equation increase. For example, the proportion of reaction (a) decreases as the pH decreases, but the total decomposition rate fluctuates greatly, i.e., becomes large, so the amount of chlorine dioxide (ClO2) generated also increases as the pH decreases. For this reason, sterilization and bleaching are faster at lower pH values, but the irritating and harmful chlorine dioxide gas (ClO2) makes the work difficult and has adverse effects on human health. In addition, the reaction of chlorous acid to chlorine dioxide proceeds quickly, the chlorous acid becomes unstable, and the time during which it maintains its bactericidal effect is extremely short.

[0057] Therefore, when adding the above-mentioned inorganic acids, inorganic acid salts, organic acids, or organic acid salts to an aqueous solution containing chlorous acid (HClO2), the pH value should be adjusted to a range of 3.2 to 8.5, or to a preferred range such as pH 3.2 to 7.0 or pH 5.0 to 7.0, depending on the purpose, from the viewpoint of suppressing the generation of chlorine dioxide and balancing it with the bactericidal effect.

[0058] When the sample is measured using a spectrophotometer, acidic chlorite ions (H) are found to exhibit a peak around 260 nm between wavelengths of 240 and 420 nm. + +ClO2 - If two absorption regions are simultaneously observed, one containing chlorine dioxide (ClO2) and the other showing a peak around 350 nm, then the presence of the chlorous acid water of the present invention can be recognized. In other words, the presence of chlorous acid (HClO2) can be confirmed. This is because, as shown in chemical formula 4 below, the solution mainly consists of chlorous acid (HClO2), chlorine dioxide (ClO2), and acidic chlorite ions (H2). + +ClO2 - This is because the cycle reactions of ) are proceeding simultaneously.

[0059] [ka]

[0060] When chlorous acid (HClO2) is converted to chlorine dioxide (ClO2), a single peak appears, almost exclusively at 350 nm.

[0061] It has been previously discovered that the pH can be further stabilized by either adding the buffer directly or by first adjusting the pH with sodium carbonate or the like and then adding the other buffer.

[0062] Therefore, in one aspect, the present invention provides a disinfectant comprising chlorous acid water, metal hydroxide, and metal phosphate.

[0063] Although we do not wish to be bound by theory, in this invention, by combining chlorine dioxide with one or more inorganic acids, inorganic acid salts, organic acids, or organic acid salts, or a combination thereof, a transition state is created, and the decomposition reaction is delayed, thereby stably maintaining chlorous acid (HClO2) for a long period of time. Unexpectedly, it has been found that this provides long-term storage and stabilization effects while maintaining the bactericidal effect. The preferred pH range can be 3.2 or more and less than 7.0, approximately 5.0 to approximately 7.5, approximately 5.0 to approximately 7.0, approximately 5.5 to approximately 7.0, approximately 5.0 to approximately 6.0, etc. The lower limit can be approximately 5.0, approximately 5.1, approximately 5.2, approximately 5.3, approximately 5.4, approximately 5.5, etc. The upper limit can be approximately 7.5, approximately 7.4, approximately 7.3, approximately 7.2, approximately 7.1, approximately 7.0, approximately 6.9, approximately 6.8, approximately 6.7, approximately 6.5, approximately 6.4, approximately 6.3, approximately 6.2, approximately 6.1, approximately 6.0, approximately 5.9, approximately 5.8, approximately 5.7, approximately 5.6, approximately 5.5, etc., but it is not limited to these. The optimal pH can be approximately 5.5, but it is not limited to these. These are not the only possible values. In this specification, when the pH value is "approximately," it means a range of plus or minus 0.05, with one decimal place as a significant figure. For example, approximately 5.5 is understood to mean between 5.45 and 5.55. In order to distinguish it from sodium chlorite, the present invention is preferably pH less than 7.0, but is by no means limited thereto.

[0064] In another context, although we do not wish to be bound by theory, the present invention has found that using potassium as the metal in a phosphate buffer is effective for maintaining chlorous acid because, compared to sodium and the like, it dissociates more easily in aqueous solution. As a result, the transition state created is maintained for a long period of time, and the effect of slowing down the progression of chlorous acid (HClO2) to chlorine dioxide (ClO2) is enhanced, therefore, it is preferable to use a potassium salt.

[0065] Preferred metal hydroxides include sodium hydroxide and / or potassium hydroxide; preferred metal phosphates include sodium phosphate (e.g., disodium hydrogen phosphate, dipotassium hydrogen phosphate, trisodium phosphate) and / or potassium phosphate (e.g., tripotassium phosphate, dipotassium hydrogen phosphate, dipotassium hydrogen phosphate; especially potassium dipotassium phosphate); and more preferably, potassium hydroxide and potassium phosphate (e.g., tripotassium phosphate, dipotassium hydrogen phosphate, dipotassium hydrogen phosphate; especially potassium dipotassium phosphate), but are not limited to these.

[0066] In preferred embodiments, the sodium hydroxide and potassium hydroxide concentrations are 0.1N to 1.0N, and the buffer pH of the sodium phosphate and potassium phosphate is 5.0 to 7.5, particularly pH 5.0 to 7.0. This is because, at these compositions and pH levels, the long-term storage stability effect is unexpectedly improved compared to previously anticipated ranges.

[0067] In one aspect, the present invention provides chlorous acid water produced by a method comprising the step of trapping chlorine dioxide (ClO2) in an aqueous solution A containing one or more inorganic acids, inorganic acid salts, organic acids, or organic acid salts, or a combination thereof. In a preferred embodiment, the chlorous acid water is produced by the method further comprising the step of adding the chlorine dioxide in the presence of hydrogen peroxide. In another preferred embodiment, in the method, the pH of the aqueous solution A is 6.0 or less and less than or equal to 11.0. In yet another preferred embodiment, the pH of aqueous solution A is 10.8 or less and 10.2 or more in the method. In yet another embodiment, the chlorine dioxide (ClO2) is provided as a gas in the method.

[0068] In one aspect, the present invention provides articles impregnated with the disinfectant of the present invention. Articles that can be used as articles of the present invention are any articles that can be impregnated with chlorous acid water and used for purposes such as disinfection, and include medical devices, etc., and include but are not limited to sheets, films, patches, brushes, nonwoven fabrics, paper, cloth, absorbent cotton, sponges, etc.

[0069] Therefore, in one aspect, the present invention provides a kit for producing chlorous acid water, comprising (1) a container containing chlorine dioxide, and (2) a container containing one or more inorganic acids, inorganic acid salts, organic acids, or organic acid salts, or a combination thereof.

[0070] In one preferred embodiment, the kit further comprises a container containing one or more of the inorganic acids, inorganic acid salts, organic acids, or organic acid salts, or a combination thereof. (2) and (3) may be the same or different.

[0071] According to the present invention, chlorous acid (HClO2) can be stably maintained for a long period of time. Although we do not wish to be bound by theory, it is thought that by using chlorine dioxide, a transition state can be created and the decomposition reaction can be slowed down. Therefore, it is thought that the lifespan of chlorous acid water produced by this method will be even longer than that of conventional methods.

[0072] According to the present invention, it is possible to stabilize chlorous acid, which has high bactericidal power, for a long period of time. As a result, aqueous solutions containing chlorous acid, so-called chlorous acid water, which were previously difficult to distribute commercially, can be put into circulation, and moreover, it can be widely used in society as a safe, useful, and simple disinfectant.

[0073] References such as scientific literature, patents, and patent applications cited herein are incorporated herein by reference to the same extent as they are specifically described herein.

[0074] The present invention has been described above with reference to preferred embodiments for ease of understanding. The present invention will now be described based on examples, but the above description and the following examples are provided for illustrative purposes only and are not intended to limit the present invention. Accordingly, the scope of the present invention is not limited to the embodiments or examples specifically described herein, but is limited only by the claims. [Examples]

[0075] Where necessary, the handling of animals used in the following examples was carried out in accordance with the Declaration of Helsinki. While the reagents used were specifically those described in the examples, equivalent products from other manufacturers (Sigma, Wako Pure Chemical Industries, Nakalai, etc.) can be substituted. In this specification, chlorous acid water may be abbreviated as "chlorous acid water," but these are synonymous.

[0076] (Conditions for producing chlorous acid water) The chlorous acid used in the following examples is produced as described below.

[0077] (Example of a manufacturing plant) An example of the manufacturing plant used is shown in Figure 1.

[0078] In Figure 1, each number corresponds to a component shown in the table below.

[0079] [Table 1]

[0080] The chlorine dioxide gas used (manufactured in-house) was 0.88%, and the acceptable range is 0.9% ± 0.1%. High concentrations are explosive and therefore dangerous, so they should be diluted by introducing nitrogen gas or similar before use. The flow rate can be adjusted using setting 5, and in this example, it is set to 210 ppm / min (210 ppm / min ± 40 ppm / min (660 mg·ClO2 / min ~ 530 mg·ClO2 / min)).

[0081] (Examples of each solution formulation) The following are examples of the formulations of each solution that may be used in this manufacturing example.

[0082] [Table 2]

[0083] [Table 3]

[0084] [Table 4]

[0085] [Table 5]

[0086] (Example 1: Production example of chlorous acid water 1 (chlorous acid water A-1)) In Example 1, chlorous acid water was produced according to the following procedure, based on the conditions for Aqueous Acid A-1 (production conditions for chlorous acid water).

[0087] (method) (1)2 was filled with the formula d. (2) Formula table a was filled into (1). The pH of this aqueous solution A was 10.8. (3)3 A tank containing 0.9% ± 0.1% chlorine dioxide gas was prepared. (4)4 was put into operation. (5) Open 5 and introduce chlorine dioxide gas into 1 at a flow rate of 210 ppm / min (210 ppm / min ± 40 ppm / min (660 mg·ClO2 / min ~ 530 mg·ClO2 / min)). (6) After 15 minutes of inflow, port 5 was closed. (7) Stopped 4 (8) Let it stand for 15 minutes. (9) Turn 4 back on and repeat steps (4) to (8) three to four times (total chlorine dioxide gas inflow time: 45 to 60 minutes). (10) The liquid in (1) was designated as chlorous acid water A-1.

[0088] (result) The test results for the manufactured product are shown below.

[0089] [Table 6]

[0090] Furthermore, the UV spectrum is shown in Figure 2. As shown in the UV spectrum, it is in a binocular state, confirming that chlorous acid water with a maintained sterilizing effect was being produced correctly.

[0091] (Example 2: Production example 1 of a chlorous acid solution (chlorous acid solution A-1)) In Example 2, a chlorous acid solution was prepared using the chlorous acid solution A-1 from Example 1, following the procedure below.

[0092] Aqueous solution B was mixed according to the following formulation.

[0093] [Table 7]

[0094] The pH at that time was 6.4.

[0095] [Table 8]

[0096] Furthermore, the UV spectrum is shown in Figure 3. As shown in the UV spectrum, it is in a binocular state, confirming that the chlorous acid solution preparation, which retains its bactericidal effect, was manufactured correctly.

[0097] (Example 3: Production Example 2 of Chlorous Acid Water (Aqueous Acid A-2)) In Example 3, chlorous acid water was produced according to the following procedure, based on the conditions for A-2 of (Production Conditions for Chlorous Acid Water).

[0098] (method) (1)2 was filled with the formula d. (2) Formula b was filled into (1). The pH of this aqueous solution A was 8.0. (3)3 A tank containing 0.9% ± 0.1% chlorine dioxide gas was prepared. (4)4 was put into operation. (5) Open 5 and introduce chlorine dioxide gas into 1 at a flow rate of 210 ppm / min (210 ppm / min ± 40 ppm / min (660 mg·ClO2 / min ~ 530 mg·ClO2 / min)). (6) After 15 minutes of inflow, port 5 was closed. (7) Stopped 4 (8) Let it stand for 15 minutes. (9) Turn 4 back on and repeat steps (4) to (8) two to three times (total chlorine dioxide gas inflow time: 30 to 45 minutes). (10) The liquid in (1) was prepared as chlorous acid water.

[0099] The test results for the manufactured product are shown below.

[0100] [Table 9]

[0101] Furthermore, the UV spectrum is shown in Figure 4. As shown in the UV spectrum, it exhibits a double-nodular structure, confirming that chlorous acid water with a maintained bactericidal effect was properly manufactured. (Example 4: Manufacturing Example 2 of Chlorous Acid Water Preparation (Chlorous Acid Preparation A-2)) In Example 4, a chlorous acid solution was prepared using the chlorous acid solution A-2 from Example 3, following the procedure below.

[0102] Aqueous solution B was mixed according to the following formulation.

[0103] [Table 10]

[0104] The pH at that time was 6.0.

[0105] [Table 11]

[0106] Furthermore, the UV spectrum is shown in Figure 5. As shown in the UV spectrum, it is in a binocular state, confirming that the chlorous acid solution preparation, which retains its bactericidal effect, was manufactured correctly.

[0107] (Example 5: Production Example 3 of Chlorous Acid Water (Aqueous Acid A-3)) In Example 5, chlorous acid water was produced according to the following procedure, based on the conditions for A-3 of (Production Conditions for Chlorous Acid Water).

[0108] (method) (1)2 was filled with the formula d. (2) Formula table c was filled into (1). The pH of this aqueous solution A was 11.0. (3)3 A tank containing 0.9% ± 0.1% chlorine dioxide gas was prepared. (4)4 was put into operation. (5) Open 5 and introduce chlorine dioxide gas into 1 at a flow rate of 210 ppm / min (210 ppm / min ± 40 ppm / min (660 mg·ClO2 / min ~ 530 mg·ClO2 / min)). (6) After 15 minutes of inflow, port 5 was closed. (7) Stopped 4 (8) Let it stand for 15 minutes. (9) Turn on 4 again and repeat steps (4) to (8) once or twice (total chlorine dioxide gas inflow time: 15 to 30 minutes). (10) The liquid in (1) was prepared as chlorous acid water.

[0109] The test results for the manufactured product are shown below.

[0110] [Table 12]

[0111] Furthermore, the UV spectrum is shown in Figure 6. As shown in the UV spectrum, it is in a binocular state, confirming that chlorous acid water with a maintained sterilizing effect was being produced correctly.

[0112] (Example 6: Production Example 3 of Chlorite Solution (Chlorite Solution A-3)) In Example 6, a chlorous acid solution was prepared using the aqueous solution A-3 from Example 5, following the procedure below. Aqueous solution B was mixed according to the following formulation.

[0113] [Table 13]

[0114] The pH at that time was 6.8.

[0115] The test results for the manufactured product are shown below.

[0116] [Table 14]

[0117] Furthermore, the UV spectrum is shown in Figure 7. As shown in the UV spectrum, it is in a binocular state, confirming that chlorous acid water with a maintained sterilizing effect was being produced correctly.

[0118] (Example 7: Bactericidal activity test and stability test) To confirm the effects of the aqueous solutions A-1 to A-2 produced in Examples 2 and 4, the following experiment was conducted.

[0119] For stability testing, a control solution was used: 6% sodium chlorite mixed with 1N hydrochloric acid to adjust the pH to 2.3-2.9 (referred to as "ASC" in this specification). This ASC, along with the two types of chlorous acid solutions prepared in Example 2 and Example 4, were stored at 4°C in a dark, sealed environment to confirm their stability.

[0120] In the sterilization efficacy confirmation test, the change in sterilization efficacy over time was confirmed immediately after manufacturing, on day 5, and on day 10, and the sterilization efficacy against Escherichia coli (E. coli) was evaluated using the carbolic acid coefficient.

[0121] To confirm the chlorous acid concentration, iodine titration was performed on ASC and two types of chlorous acid water produced in Example 2 and Example 4 on day 1, day 5, and day 10 to determine the chlorous acid concentration.

[0122] The results are shown below.

[0123] [Table 15-1]

[0124] [Table 15-2]

[0125] [Table 15-3]

[0126] [Table 16-1]

[0127] [Table 16-2]

[0128] [Table 16-3]

[0129] [Table 17-1]

[0130] [Table 17-2]

[0131] [Table 17-3]

[0132] One advantage of using chlorine dioxide gas is that it creates a transition state, slowing down the decomposition reaction and allowing chlorous acid (HClO2) to be kept stable and maintained for a long period of time.

[0133] Figure 8 shows the results of these analyses in a graph.

[0134] As shown in Tables 15-1 to 15-3 and Figure 8, the control ASC chlorite The concentration had almost completely disappeared by the fifth day, and the bactericidal effect of E. coli had also ceased. On the other hand, as shown in Tables 16-1 to 16-3, Tables 17-1 to 17-3 and Figure 8, although the chlorous acid concentration of chlorous acid water preparation A-1 and chlorous acid water preparation A-2 decreased rapidly immediately after production, it remained stable thereafter, albeit with some decrease, and the bactericidal effect against E. coli was maintained. Comparing the data immediately after production and after 10 days, there was almost no difference in bactericidal effect, so it is understood that this is a method for producing chlorous acid water that can stably exhibit a bactericidal effect for at least 10 days. Although we do not wish to be bound by theory, this proves that the chlorous acid water produced by the method of the present invention can maintain chlorous acid (HClO2) stably in an aqueous solution for a long period of time by creating a transition state and delaying the decomposition reaction.

[0135] As described above, the present invention has been illustrated using preferred embodiments and examples, but the present invention is not limited thereto and can be implemented in various ways within the scope of the configuration described in the claims, and it is understood that the scope of the present invention should be interpreted solely in accordance with the claims. It is understood that the patents, patent applications and documents cited herein should be incorporated as reference to this specification, just as their contents are specifically described herein. [Industrial applicability]

[0136] The aqueous solution containing chlorous acid obtained by this invention can be used not only as a disinfectant, but also as a deodorant, bleach, blood-draining agent, and for other purposes.

Claims

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