Method for producing aqueous solution containing chlorous acid to be used as disinfectant

Abstract

To provide a method for producing an aqueous solution containing chlorous acid to be used as a disinfectant, by generating chlorous acid which is safe to the human body as a preprocessing disinfectant of food processing, is easy to handle, and generates less chlorine dioxide.SOLUTION: Provided is a method for producing an aqueous solution containing chlorous acid to be used as a disinfectant, by generating chlorous acid which is safe to the human body as a preprocessing disinfectant of food processing, is easy to handle, and generates less chlorine dioxide. The chlorous acid is generated by adding to an aqueous solution of sodium chlorate, sulphuric acid or its aqueous solution of an amount and a concentration allowing keeping the pH value of the aqueous solution within 2.3 to 3.4, and reacting them so as to generate chloric acid, and adding hydrogen peroxide of an amount equal to or more than an amount required for a reductive reaction to the chloric acid.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing an aqueous solution containing chlorous acid, which is used for sterilizing and disinfecting food and related facilities in the pretreatment stage of food processing. [Background technology]

[0002] Conventionally, chlorine oxides (chlorine, hypochlorous acid, chlorous acid, chlorine dioxide, etc.) have been mainly used for sterilization and disinfection of foods in the pretreatment stage of food processing, such as fresh foods such as vegetables and fruits, and related facilities for processing and manufacturing these foods, such as containers, processing and cooking machines, factory equipment, etc. Among these, it has been pointed out that chlorine and hypochlorous acid produce trihalomethanes, which are carcinogenic substances, when they react with organic compounds. For this reason, coupled with recent health consciousness, attention has been paid to acidified chlorites (ACs), which were developed in the United States and have less adverse effects of trihalomethanes and a high bactericidal effect.

[0003] To obtain the acidified chlorite (AC), it is necessary to add a GRAS (Generally Recognized As Safe) acid to the aqueous sodium chlorite solution and adjust the pH value to 2.3 to 3.2.

[0004] However, chlorous acid, which is the main component of the acidified chlorite (AC), is unstable and decomposes in a short time after preparation, resulting in a significant decrease in bactericidal activity. Therefore, when using the acidified chlorite (AC), it is necessary to perform an adjustment operation immediately before using it.

[0005] This is not only time-consuming, but also has the disadvantage that chlorine dioxide gas may be generated during preparation, which may be harmful to the human body if inhaled, and may also corrode food processing and cooking equipment. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] United States Patent No. 6,524,624 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above-mentioned drawbacks, and an object of the present invention is to provide a pretreatment disinfectant for food processing which can stabilize an aqueous solution containing chlorous acid for a long period of time, thereby making it easy to handle, suppressing the generation of chlorine dioxide, and being safe to the human body and having excellent disinfecting power. [Means for solving the problem]

[0008] In order to achieve the above object, the first feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is to generate chlorous acid by adding sulfuric acid or an aqueous solution thereof to an aqueous solution of sodium chlorate in an amount and concentration that can maintain the pH value of the aqueous solution within a range of 2.3 to 3.4, and reacting the aqueous solution to generate chlorous acid, and then adding hydrogen peroxide in an amount equal to or greater than the amount required for the reduction reaction of the chlorous acid to generate chlorous acid.

[0009] The second feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that sulfuric acid or an aqueous solution thereof is added to an aqueous solution of sodium chlorate in an amount and concentration capable of maintaining the pH value of the aqueous solution within a range of 2.3 to 3.4, and reacted to generate chloric acid, and then hydrogen peroxide is added in an amount equal to or greater than the amount required for the reduction reaction of the chloric acid to generate the aqueous solution of chlorous acid, and then any one of inorganic acids or inorganic acid salts, or two or more of them alone or in combination, is added to the aqueous solution to adjust the pH value to within a range of 3.2 to 7.0.

[0010] Furthermore, a third feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that sulfuric acid or an aqueous solution thereof is added to an aqueous solution of sodium chlorate in an amount and concentration capable of maintaining the pH value of the aqueous solution within a range of 2.3 to 3.4, and reacted to generate chloric acid, and then hydrogen peroxide is added in an amount equal to or greater than the amount required for the reduction reaction of the chloric acid to generate the aqueous solution of chlorous acid, and then an inorganic acid, an inorganic acid salt, an organic acid, or an organic acid salt is added alone or in combination with two or more of them to adjust the pH value to within a range of 3.2 to 7.0.

[0011] Furthermore, the fourth feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that sulfuric acid or an aqueous solution thereof is added to an aqueous solution of sodium chlorate in an amount and concentration capable of maintaining the pH value of the aqueous solution within a range of 2.3 to 3.4, and reacted to generate chloric acid, and then hydrogen peroxide is added in an amount equal to or greater than the amount required for the reduction reaction of the chloric acid to generate the aqueous solution of chlorous acid, and then any one or two or more of an inorganic acid or an inorganic acid salt are added alone or in combination with each other to the aqueous solution of chlorous acid, and then any one or two or more of an inorganic acid or an inorganic acid salt are added alone or in combination with each other to the aqueous solution of chlorous acid to adjust the pH value to within a range of 3.2 to 7.0.

[0012] In addition, a fifth feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that the inorganic acid in the method for producing an aqueous solution containing chlorous acid according to any one of the second to fourth features is carbonic acid, phosphoric acid, boric acid or sulfuric acid.

[0013] Furthermore, a sixth feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that the inorganic acid salt in the method for producing an aqueous solution containing chlorous acid according to any one of the second to fifth features is a carbonate, a hydroxide, a phosphate or a borate.

[0014] In addition, a seventh feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that the carbonate in the method for producing an aqueous solution containing chlorous acid according to the sixth feature is sodium carbonate, potassium carbonate, sodium hydrogen carbonate, or potassium hydrogen carbonate.

[0015] Furthermore, an eighth feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that the hydroxide salt in the method for producing an aqueous solution containing chlorous acid according to the sixth or seventh feature is sodium hydroxide or potassium hydroxide.

[0016] Furthermore, a ninth feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that the phosphate in the method for producing an aqueous solution containing chlorous acid according to any one of the sixth to eighth features is disodium hydrogen phosphate, sodium dihydrogen phosphate, trisodium phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, or potassium dihydrogen phosphate.

[0017] In addition, a tenth feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that the borate in the method for producing an aqueous solution containing chlorous acid according to any one of the sixth to ninth features is sodium borate or potassium borate.

[0018] Furthermore, an eleventh feature of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that the organic acid in the method for producing an aqueous solution containing chlorous acid according to any one of the third to tenth features is succinic acid, citric acid, malic acid, acetic acid, or lactic acid.

[0019] Furthermore, a twelfth characteristic of the method for producing an aqueous solution containing chlorous acid to be used as a disinfectant according to the present invention is that the organic acid salt in the method for producing an aqueous solution containing chlorous acid according to any one of the third to eleventh characteristics is sodium succinate, potassium succinate, sodium citrate, potassium citrate, sodium malate, potassium malate, sodium acetate, potassium acetate, sodium lactate, potassium lactate, or calcium lactate. Effect of the Invention

[0020] According to the present invention, since the chlorous acid having high bactericidal power is maintained for a long time, it is not necessary to adjust the amount of the acid just before use, and it can be stored. It is also possible to suppress the generation of chlorine dioxide, which is safe for the human body and can be used with confidence.

[0021] In addition, since it becomes possible to maintain chlorous acid for a long period of time, it is quite possible to distribute an aqueous solution containing chlorous acid that has been produced in advance in an acidic range as a product. [Brief description of the drawings]

[0022] [Figure 1] This shows the results of spectrophotometer measurement of sample A on the day the sample was prepared. [Diagram 2] This shows the results of spectrophotometric measurement of sample A on the 10th day after the sample was created. [Diagram 3] This shows the results of spectrophotometric measurement of sample A on the 20th day after the sample was created. [Figure 4] This shows the results of spectrophotometric measurement of sample A on the 30th day from the date of sample creation. [Diagram 5] This shows the spectrophotometer measurement results of sample B on the day the sample was prepared. [Figure 6] This shows the results of spectrophotometric measurement of sample B on the 10th day from the date of sample preparation. [Figure 7] This shows the results of spectrophotometric measurement of sample B on the 20th day from the date of sample creation. [Figure 8] This shows the results of spectrophotometric measurement of sample B on the 30th day from the date of sample creation. [Figure 9] This shows the spectrophotometer measurement results of sample C on the day the sample was prepared. [Figure 10] This shows the results of spectrophotometric measurement of sample C one hour after sample preparation. [Figure 11] This shows the results of spectrophotometric measurement of sample C one day after the sample was prepared. [Figure 12] This shows the results of spectrophotometric measurement of sample C on the fifth day after the sample preparation date. [Figure 13] This shows the spectrophotometer measurement results of sample D on the day the sample was prepared. [Figure 14] This shows the results of measurement of sample D using a spectrophotometer on the 10th day after the sample was created. [Figure 15] This shows the results of spectrophotometric measurement of sample D on the 20th day from the date of sample preparation. [Figure 16] This shows the results of measurement of sample D using a spectrophotometer on the 30th day after the date of sample creation. [Figure 17] FIG. 1 is a graph comparing the change in pH over days of aqueous solutions containing chlorous acid according to Examples 2, 3, and 4 and ASC, which is a conventional example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings and tables. EXAMPLES

[0024] Example 1 of the present invention is a method for producing a chlorine-containing bactericide, HClO 2 This method is a method for producing an aqueous solution containing sodium chlorate (NaClO 3 ) in a solution of sulfuric acid (H 2 SO 4 ) or its aqueous solution to create acidic conditions. 3) is reduced to chlorous acid by adding an excess of hydrogen peroxide in an amount necessary to produce chlorous acid (HClO 2 The basic chemical reactions in this manufacturing process are shown in the following formulas A and B.

[0025] [ka]

[0026] In formula A, sodium chlorate (NaClO 3 Sulfuric acid (H) in an amount and concentration that will keep the pH value of the aqueous solution within 2.3 to 3.4 2 SO 4 ) or its aqueous solution to obtain chloric acid and simultaneously remove sodium ions.

[0027] Next, in Equation B, chloric acid (HClO 3 ) is hydrogen peroxide (H 2 O 2 ) and reduced by chlorous acid (HClO 2 In this case, the amount of hydrogen peroxide (water) added must be equal to or greater than the amount required for the reduction reaction. If the amount is less than this, only chlorine dioxide will be generated.

[0028] [ka]

[0029] In the unlikely event that chlorine dioxide is generated, chlorous acid is produced via the C to F reactions.

[0030] By the way, the generated chlorous acid (HClO 2 ) occurs when multiple chlorous acid molecules decompose with each other or produce chloride ions (Cl -In the presence of chlorous acid (HClO), hypochlorous acid (HClO) and other reducing agents, it decomposes quickly into chlorine dioxide gas and chlorine gas. Therefore, in order to make it useful as a disinfectant, 2 ) state for a long period of time.

[0031] Therefore, the chlorous acid (HClO 2 By adding inorganic acids, inorganic acid salts, organic acids or organic acid salts, either alone or in combination, to an aqueous solution containing chlorous acid (HClO), a transition state is created, which delays the decomposition reaction and allows the decomposition of chlorous acid (HClO) to proceed for a long period of time. 2 A method for producing an aqueous solution capable of stably maintaining the above-mentioned pH is required, and this is shown in Examples 2, 3, and 4. EXAMPLES

[0032] That is, Example 2 is a method for producing chlorous acid (HClO 2 To an aqueous solution containing the above-mentioned compound, an inorganic acid or an inorganic salt, specifically a carbonate or hydroxide salt, is added either alone or in combination with two or more kinds of the above. EXAMPLES

[0033] In Example 3, an inorganic acid, an inorganic acid salt, an organic acid or an organic acid salt is added to the aqueous solution produced in Example 2, either alone or in combination of two or more kinds. EXAMPLES

[0034] In Example 4, an inorganic acid or an inorganic acid salt, or an organic acid or an organic acid salt is added to the aqueous solution produced in Example 1, either alone or in combination of two or more kinds.

[0035] Examples of the inorganic acid include carbonic acid, phosphoric acid, boric acid, and sulfuric acid. Examples of inorganic acid salts include carbonates, hydroxides, and phosphates and borates. More specifically, the carbonates include sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate, the hydroxides include sodium hydroxide and potassium hydroxide, the phosphates include disodium hydrogen phosphate, sodium dihydrogen phosphate, trisodium phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, and potassium dihydrogen phosphate, and the borates include sodium borate and potassium borate. Examples of the organic acid include succinic acid, citric acid, malic acid, acetic acid, and lactic acid. Examples of the organic acid salts include sodium succinate, potassium succinate, sodium citrate, potassium citrate, sodium malate, potassium malate, sodium acetate, potassium acetate, sodium lactate, potassium lactate, and calcium lactate.

[0036] In Examples 2, 3 and 4, Na + +ClO 2 - ⇔ NaClO 2 Or K + +ClO 2 - ⇔ KClO 2 Or H + +ClO 2 - ⇔ H-ClO 2 This creates a transition state, resulting in the formation of chlorous acid (HClO 2 ) of chlorine dioxide (ClO 2 This slows down the progression of chlorous acid (HClO 2 ) for a long time, and chlorine dioxide (ClO 2 It is possible to produce an aqueous solution containing chlorous acid with little generation of chlorine.

[0037] Incidentally, it is recognized that the lower the pH value of chlorine oxide (the stronger the acidity), the stronger its bactericidal power. The table below shows the results of an experiment on the relationship between pH value and bactericidal power. Here, pathogenic Escherichia coli (Eschrichia coli O157:H7) was used as the bacterial strain, and sodium chlorite (80% manufactured by Wako Pure Chemical Industries, Ltd.) was used as the test chlorine oxide, and citric acid (98% manufactured by Wako Pure Chemical Industries, Ltd.), lactic acid (85-92% manufactured by Wako Pure Chemical Industries, Ltd.), and acetic acid (99.7% manufactured by Wako Pure Chemical Industries, Ltd.) were used as activators. Then, citric acid, lactic acid, and acetic acid were added to 30 ml of sodium chlorite aqueous solution (0.5 g / l) (pH 9.8) to adjust the pH to 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, and 8.0, respectively, and 10 ml of the appropriately diluted test solution was placed in a test tube using the phenol coefficient measurement method and kept warm in a constant temperature water bath at 20 ± 1°C for more than 5 minutes. Then, 1 ml of the bacterial solution that had been kept warm in the same way was injected into the test tube, and after 2.5, 5, 10, and 15 minutes, a platinum loopful was removed and inoculated into normal bouillon medium. After culturing at 37°C for 48 hours, the growth of the bacteria was observed with the naked eye, and growth was marked as (+) and no growth was marked as (-).

[0038] [Table 1]

[0039] [Table 2]

[0040] [Table 3]

[0041] As can be seen from the above table, sodium chlorite aqueous solution with a pH of 7.0 or higher was unable to sterilize the test bacteria E. coli even after 15 minutes of action, but by adjusting the pH to 4.0 or lower, it sterilized in 2.5 minutes, by adjusting to 5.0, it sterilized in 10 minutes, and by adjusting to 6.0, it sterilized in 15 minutes. From this, the bactericidal effect of sodium chlorite aqueous solution increases as the pH becomes more acidic. In addition, no significant difference was observed in the bactericidal effect of sodium chlorite due to the difference in activator.

[0042] Thus, the stronger the acidity of a chlorite aqueous solution, the stronger its bactericidal power. However, when the acidity is high, for example at a pH value of 2, it can cause adverse effects such as denaturation of proteins in the target foods during sterilization, limiting its scope of use in the food industry.

[0043] [ka]

[0044] The above chemical formula 2 represents the decomposition of chlorite in an acidic solution, and the decomposition rate of the chlorite aqueous solution at pH is higher as the pH is lower, i.e., the stronger the acidity is, the higher the decomposition rate of the chlorite aqueous solution. In other words, the absolute rates of reactions (a), (b), and (c) in the above formula increase. For example, the proportion of reaction (a) decreases as the pH is lowered, but the total decomposition rate fluctuates greatly, i.e., becomes large, so that ClO 2 The amount of chlorine dioxide (ClO2) generated also increases with decreasing pH. Therefore, the lower the pH value, the faster the sterilization and bleaching will occur, but the amount of irritating and harmful ClO2 will also increase. 2 The gas makes work difficult and has adverse effects on human health. In addition, the reaction of chlorous acid with chlorine dioxide proceeds quickly, making the acid unstable and shortening the time it can maintain its bactericidal power.

[0045] Therefore, chlorous acid (HClO 2When the inorganic acid, inorganic acid salt, organic acid or organic acid salt is added to an aqueous solution containing sodium chlorite (NaClO), the pH value is adjusted to within the range of 3.2 to 7.0 from the viewpoint of the balance between the inhibition of chlorine dioxide generation and the bactericidal power. However, if there is no problem with the bactericidal power, it is desirable to set the pH value as high as possible within the above range. This allows the aqueous solution to have a high pH value, which is suitable for preventing sodium chlorite (NaClO 2 ) and slows the progression to chlorous acid (HClO 2 ) for a long time, and chlorine dioxide (ClO 2 It is possible to produce an aqueous solution containing chlorous acid with little generation of chlorine.

[0046] In order to confirm the effects of the present invention, experiments were carried out using the following samples. First, 1 mol / l sodium carbonate was added to the chlorous acid obtained according to Example 1 to adjust the pH to 5.7 (corresponding to Example 2), and the solution was poured into a 0.05 mol / l sodium borate / succinic acid (pH 5.7) buffer solution to adjust the chlorous acid content to 3%. That is, an inorganic salt was added to an aqueous solution containing chlorous acid, and then a combination of an inorganic acid salt and an organic acid salt was added as a buffer solution (corresponding to Example 3), and this was designated as sample A.

[0047] Next, 1 mol / l sodium carbonate was added to the chlorous acid obtained according to Example 1 to adjust the pH to 5.7, and then the chlorous acid content was adjusted to 3% with deionized water. That is, an inorganic acid salt was added to an aqueous solution containing chlorous acid (corresponding to Example 2), and this was designated as sample B.

[0048] Furthermore, a 1 mol / L citric acid (98% product, Wako Pure Chemical Industries, Ltd.) solution was added to an aqueous solution (25.0%) of sodium chlorite (80% product, Wako Pure Chemical Industries, Ltd.) to adjust the pH to 2.6, and the chlorous acid content was adjusted to 3% with deionized water. That is, this is the conventional technology equivalent to the above AC, and this was designated as sample C.

[0049] Also, the chlorous acid obtained according to Example 1 was added to a 0.05 mol / l sodium borate / succinic acid (pH 6.8) buffer solution to make the final pH 5.7 and the content of chlorous acid 3%. That is, an aqueous solution containing chlorous acid was added with a combination of an inorganic acid salt and an organic acid salt as a buffer solution (corresponding to Example 4), and this was designated as sample D.

[0050] And each chlorous acid (HClO 2 The stability of chlorous acid (HClO) was compared by measuring the UV spectrum and content over time. 2 ) content was set to 3% in all cases. The UV spectrum was measured using a spectrophotometer that was adjusted to dilute the specimen with ion-exchange water as appropriate and have an absorbance of about 1 at the maximum absorption wavelength. The content was measured using the iodometric titration method shown below. That is, the specimen was aerated in a gas washing container to wash and remove the chlorine dioxide gas from the product, and then approximately 10 g of the product was precisely weighed out and water was added to make exactly 100 ml to use as the sample solution. Chlorous acid (HClO 2 ), accurately weigh out an amount of sample equivalent to about 0.06 g, place in an iodine bottle, add 12 ml of sulfuric acid (3 → 100), add water to make the volume about 55 ml, add 4 g of potassium iodide, immediately seal the bottle, and leave in a dark place for 15 minutes. Titrate with 0.1 mol / l sodium thiosulfate to obtain the formula (1 ml of 0.1 mol / l sodium thiosulfate solution = 0.001711 g HClO 2 ) was used to determine the content of chlorous acid in the solution (indicator starch test solution). A blank test was also performed separately to make corrections. The test was performed in a dark room, and the chlorous acid content, UV measurement, and pH were measured immediately after preparation and after 1, 2, 3, 24, 48, 72, 96, 120, 240, 480, and 720 hours.

[0051] As a result, immediately after the preparation of samples A, B, C, and D, the acidic chlorite ion (H + +ClO 2 -) and chlorine dioxide (ClO 2 Since two absorption areas containing chlorous acid (HClO 2 ) can be seen (Figures 1, 5, 9, and 13). This is because, as shown in the following chemical formula 4, 2 ), and chlorine dioxide (ClO 2 ), and acidified chlorite ion (ClO 2 - ) cycle reactions are proceeding simultaneously.

[0052] [ka]

[0053] However, in sample C, although the two peaks were clearly visible for up to 1 hour (Figure 10), after 24 hours the two peaks were barely visible (Figure 11), and thereafter there was only a single peak at 350 nm (Figure 12). This shows that chlorous acid had been converted to chlorine dioxide.

[0054] On the other hand, it can be seen that samples A, B, and D have two peaks at around 260 nm and 350 nm even after 30 days (Figures 4, 8, and 16). Therefore, it can be said that the aqueous solution containing chlorous acid produced by the present invention is considerably more stable in terms of chlorous acid than the conventional example.

[0055] Of these, in specimen B, in Figures 5, 6, 7, and 8, which show the state of the UV curve over time, it can be seen that the two peaks change as the days go by from 10 to 30. On the other hand, it can be seen that specimens A and D can maintain the two peaks from day 0 even after 30 days (Figures 1, 2, 3, 4, 13, 14, 15, and 16). From this, it can be seen that the components of chlorous acid, chlorite ion, chlorine dioxide, and other chlorine oxides have hardly changed in specimens A and D, and it can be seen that the state of the contents in the aqueous solution is better maintained in Example 3 (addition of inorganic acid salt + organic acid or organic acid salt) or Example 4 (organic acid or organic acid salt) than in Example 2 (addition of inorganic acid salt).

[0056] Table 4 shows the change in the content of chlorous acid. Here, the content of sample C, which is AC, was halved 2 hours after preparation, and almost all of the chlorous acid had disappeared by the fourth day. On the other hand, samples A, B, and D still contained a large amount of chlorous acid even after 30 days. Therefore, it is shown that the aqueous solution containing chlorous acid produced by the present invention has an advantage in that chlorous acid is maintained for a long time compared to the conventional example.

[0057] Of these, it can be seen that the chlorous acid content of samples A and D on day 0 can be maintained for approximately 30 days. This shows that the aqueous solutions containing chlorous acid produced in Examples 3 and 4 have the greatest ability to stably retain chlorous acid for a long period of time.

[0058] [Table 4]

[0059] FIG. 17 shows the change in pH value over time for samples A, B, C, and D. Here, sample B was adjusted to pH 5.7 immediately after preparation, but the pH rose to the 6 range once and then tended to decrease. On the other hand, sample A maintained its pH of 5.8 on day 0 even after 30 days, demonstrating its buffering power. At the same time, sample D maintained its pH of 5.7 on day 0 even after 30 days, demonstrating its buffering power. From the above, it is shown that the pH can be stabilized more by directly adding a buffering agent, or by adjusting the pH once with sodium carbonate and then adding another buffering agent.

[0060] From the above, it was found that the aqueous solution obtained by simply acidifying the aqueous solution of sodium chlorite by AC rapidly produces chlorine dioxide (ClO 2 ) to chlorous acid (HClO 2 However, the aqueous solution obtained by the present invention maintains the pH within a certain range, and adjusts the amount of hydrogen ions that is insufficient or excessive due to the oxidation-reduction reaction of chlorine oxide. As a result, the pH is stabilized, and the transition state of subchlorine oxide is lost. Oxygen acid (HClO 2 ), that is, H + ·ClO 2 ⇔HClO 2 It was found that this state exists for a long time, which maintains the balance of molecules and ions in the aqueous chlorous acid solution, thereby maintaining the chlorous acid content. This shows that chlorous acid (HClO 2 It can be said that the method of the present invention is an unprecedented and extremely superior method for producing an aqueous solution containing

[0061] According to the present invention, since chlorous acid, which has a high bactericidal power, can be stabilized for a long period of time, it becomes possible to put an aqueous solution containing chlorous acid, which has been difficult to distribute generally as a product, into the distribution process, and chlorous acid, which is useful as a bactericide, can be disseminated in society.

[0062] Although the embodiments of the present invention have been described in detail above with reference to the drawings and tables, the present invention is not limited thereto and can be embodied in various forms within the scope of the configuration described in the claims. [Industrial Applicability]

[0063] The aqueous solution containing chlorous acid obtained by the present invention can be used as a disinfectant, as well as a bleaching agent, a blood removing agent, and the like.

Claims

[Claim 1] A method for producing the aqueous solution described in this specification.

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