Chlorine dioxide generating device and chlorine dioxide generating method

Abstract

Provided is a chlorine dioxide generation device (X) in which chlorine dioxide gas is generated by mixing, in a solvent in a container (1), a chlorite salt, an acidic substance that reacts with the chlorite salt to generate chlorine dioxide gas, and a buffer action substance that is a salt or conjugate base thereof that buffers the acidic substance.

Description

This divisional application is a divisional application of a patent application with an application date of August 27, 2020, an application number of 202080059504.4, a publication number of CN114269465A, and an invention title of "Chlorine Dioxide Generation Device and Chlorine Dioxide Generation Method". This patent application entered China through the PCT route, with an international application number of PCT / JP2020 / 032402 and an international publication number of WO2021 / 044943, claiming the priority date of September 2, 2019 of JP2019159368A of the Japan Patent Office. Technical Field

[0001] The present invention relates to a chlorine dioxide generation device and a chlorine dioxide generation method for generating chlorine dioxide gas in a solvent within a container. Background Art

[0002] Heretofore, devices and apparatuses for generating chlorine dioxide gas by reacting a solution of chlorite with an acidic substance have been known (for example, Patent Document 1). Prior Art Documents Patent Documents

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2007-145654. Summary of the Invention Problems to be Solved by the Invention

[0004] In the method for generating chlorine dioxide gas described in Patent Document 1, a large amount of high-concentration chlorine dioxide gas is generated, for example, at the initial stage of the reaction, and low-concentration chlorine dioxide gas is generated after a certain period of time. For example, when it is desired to disinfect a room, indoor area, or other similar space with chlorine dioxide gas in an environment where people are present, it is necessary to stably generate a certain degree of low-concentration chlorine dioxide gas for a long time from the initial stage of the reaction.

[0005] Therefore, an object of the present invention is to provide a chlorine dioxide generation device and a chlorine dioxide generation method capable of stably controlling and generating chlorine dioxide gas from the initial stage of the reaction. Means for Solving the Problems

[0006] The chlorine dioxide generation device of the present invention for achieving the above object is characterized in that in a solvent within a container, a chlorite, an acidic substance that reacts with the chlorite to generate chlorine dioxide gas, and a buffering substance that is a salt or conjugate base thereof having a buffering action on the acidic substance are mixed to generate chlorine dioxide gas.

[0007] In the chlorine dioxide generating device of the present invention, a chlorite and an acidic substance react in a solvent in a container to generate chlorine dioxide gas. At this time, since there is a buffering substance in the solvent that is a salt or conjugate base thereof having a buffering effect on the acidic substance, when the chlorite and the acidic substance react to generate chlorine dioxide, the pH of the solvent can be made not to change easily (substantially fixed). Therefore, it is possible to stably control and generate chlorine dioxide gas from the initial stage of the reaction between the chlorite and the acidic substance.

[0008] In the following Example 1 etc., when a buffering substance is added to the reaction system of the chlorite and the acidic substance, the following results are obtained: At the initial stage of the reaction, low-concentration chlorine dioxide gas is generated, and subsequently, the production amount of chlorine dioxide gas remains substantially at the low concentration of the initial stage of the reaction for a long time. On the other hand, when no buffering substance is added to the reaction system of the chlorite and the acidic substance, the following results are obtained: At the initial stage of the reaction, high-concentration chlorine dioxide gas is rapidly generated in large quantities, and subsequently, the production amount of chlorine dioxide gas rapidly decreases.

[0009] Therefore, in the case where a buffering substance is added to the reaction system of the chlorite and the acidic substance as in the chlorine dioxide generating device of the present invention, compared with the case where no buffering substance is added, the concentration of chlorine dioxide gas at the initial stage of the reaction can be suppressed, and thus, the production period can be dramatically extended while maintaining the production concentration of chlorine dioxide gas at the initial stage of the reaction.

[0010] A further characteristic configuration of the chlorine dioxide generating device of the present invention is that the chlorite is sodium chlorite or potassium chlorite, and the acidic substance is any one of inorganic acids, organic acids, and amphiphilic substances.

[0011] According to this configuration, sodium chlorite or potassium chlorite as the chlorite is easily available, so the present invention can be easily realized. In addition, if the acidic substance is any one of inorganic acids, organic acids, and amphiphilic substances, it can react with sodium chlorite or potassium chlorite as the chlorite to generate chlorine dioxide.

[0012] A further characteristic configuration of the chlorine dioxide generating device of the present invention is that the acidic substance is a phosphoric acid compound.

[0013] According to this configuration, if the acidic substance is a phosphoric acid compound, it is easily available, so the present invention can be easily implemented.

[0014] A further characteristic configuration of the chlorine dioxide generating device of the present invention is that the acidic substance is sodium dihydrogen phosphate or potassium dihydrogen phosphate.

[0015] According to this composition, sodium dihydrogen phosphate or potassium dihydrogen phosphate as an acidic substance has excellent storage stability, does not generate corrosive gases, and has excellent operability. Therefore, it is easy to implement the present invention.

[0016] A further characteristic composition of the chlorine dioxide generating device of the present invention is that the buffering substance is a phosphate.

[0017] According to this composition, if the buffering substance is a phosphate, it can reliably buffer the phosphoric acid compound (sodium dihydrogen phosphate or potassium dihydrogen phosphate) as an acidic substance in the solvent in the container.

[0018] A further characteristic composition of the chlorine dioxide generating device of the present invention is that the buffering substance contains at least any one of tripotassium phosphate, trisodium phosphate, dipotassium hydrogen phosphate, and disodium hydrogen phosphate.

[0019] According to this composition, tripotassium phosphate, trisodium phosphate, dipotassium hydrogen phosphate, and disodium hydrogen phosphate as buffering substances are easily obtained. Therefore, it is easy to implement the present invention.

[0020] A further characteristic composition of the chlorine dioxide generating device of the present invention is that the acidic substance is acetic acid.

[0021] According to this composition, if the acidic substance is acetic acid, it is easily obtained, has excellent storage stability, does not generate corrosive gases, and has excellent operability. Therefore, it is easy to implement the present invention.

[0022] A further characteristic composition of the chlorine dioxide generating device of the present invention is that the buffering substance is an acetate.

[0023] According to this composition, if the buffering substance is an acetate, it can reliably buffer acetic acid as an acidic substance in the solvent in the container.

[0024] A further characteristic composition of the chlorine dioxide generating device of the present invention is that the buffering substance contains at least any one of potassium acetate and sodium acetate.

[0025] According to this composition, potassium acetate and sodium acetate as buffering substances are easily obtained. Therefore, it is easy to implement the present invention.

[0026] A further characteristic composition of the chlorine dioxide generating device of the present invention is that the acidic substance is citric acid.

[0027] According to this composition, if the acidic substance is citric acid, it is easily obtained, has excellent storage stability, does not generate corrosive gases, and has excellent operability. Therefore, it is easy to implement the present invention.

[0028] A further characteristic composition of the chlorine dioxide generating device of the present invention lies in that the buffering substance is a citrate.

[0029] According to this composition, if the buffering substance is a citrate, it can reliably buffer citric acid, which is an acidic substance, in the solvent in the container.

[0030] A further characteristic composition of the chlorine dioxide generating device of the present invention lies in that the buffering substance contains at least any one of potassium citrate and sodium citrate.

[0031] According to this composition, potassium citrate and sodium citrate, which are used as the buffering substance, are easily obtainable. Therefore, it is easy to implement the present invention.

[0032] A further characteristic composition of the chlorine dioxide generating device of the present invention lies in that the pH of the solvent is 5 to 7.

[0033] According to this composition, by setting the pH of the solvent to 5 to 7, it is possible to more stably control and generate low-concentration chlorine dioxide gas from the initial stage of the reaction (see Example 5 below).

[0034] A further characteristic composition of the chlorine dioxide generating device of the present invention lies in that the chlorite is in the form of an aqueous chlorite solution, and the concentration of the chlorite is 3 to 25% by weight.

[0035] In Example 2 below, when observing the production amount of chlorine dioxide gas when various changes (3 to 25% by weight) are made to the concentration of the aqueous chlorite solution, the following results are obtained: it is possible to suppress the concentration of chlorine dioxide gas in the initial stage of the reaction, and it is possible to dramatically extend the production period while maintaining the production concentration of chlorine dioxide gas in the initial stage of the reaction. Therefore, considering safety, stability, the production efficiency of chlorine dioxide gas, etc., the concentration of the chlorite can be 3 to 25% by weight.

[0036] A further characteristic composition of the chlorine dioxide generating device of the present invention lies in that a gelling agent is added to the solvent in the container.

[0037] According to this composition, by adding the gelling agent, the solvent in the container can be gelled. Therefore, even if the container is tilted, the gelled solvent is not easily spilled from the container, and thus the chlorine dioxide generating device can be easily operated.

[0038] The characteristic composition of the method for producing chlorine dioxide according to the present invention lies in that in a solvent within a container, a chlorite, an acidic substance that reacts with the chlorite to generate chlorine dioxide gas, and a buffering substance which is a salt or conjugate base thereof having a buffering effect on the acidic substance are mixed to generate chlorine dioxide gas.

[0039] In the method for producing chlorine dioxide according to the present invention, the chlorite and the acidic substance react in the solvent within the container to generate chlorine dioxide gas. At this time, since there is a buffering substance which is a salt or conjugate base thereof having a buffering effect on the acidic substance in the solvent, when the chlorite and the acidic substance react to form chlorine dioxide, the pH of the solvent is not likely to change (substantially fixed). Therefore, it is possible to stably control and generate chlorine dioxide gas from the initial stage of the reaction between the chlorite and the acidic substance.

[0040] Therefore, in the case where a buffering substance is added to the reaction system of the chlorite and the acidic substance as in the method for producing chlorine dioxide according to the present invention, compared with the case where no buffering substance is added, it is possible to suppress the concentration of chlorine dioxide gas in the initial stage of the reaction, and thus it is possible to significantly extend the production period while maintaining the production concentration of chlorine dioxide gas in the initial stage of the reaction.

[0041] A further characteristic composition of the method for producing chlorine dioxide according to the present invention lies in that the acidic substance is mixed in a state where the buffering substance is dissolved in an aqueous solution of chlorite.

[0042] According to this composition, by dissolving the buffering substance in the aqueous solution of chlorite, it is possible to make the buffering substance in a uniform state in the aqueous solution of chlorite. If the acidic substance is mixed in this state, when the chlorite and the acidic substance react to form chlorine dioxide, the pH of the solvent is even less likely to change. Therefore, it is possible to reliably suppress the concentration in the initial stage of the reaction, and thus it is possible to further extend the production period while maintaining the production concentration of chlorine dioxide gas in the initial stage of the reaction.

[0043] A further characteristic composition of the method for producing chlorine dioxide according to the present invention lies in that the acidic substance and a gelling agent are mixed in a state where the buffering substance is dissolved in an aqueous solution of chlorite.

[0044] According to this composition, by adding a gelling agent, it is possible to gel the solvent within the container. Therefore, even if the container is tilted, the gelled solvent is not likely to spill out of the container and can hold... The method for producing chlorine dioxide can be carried out more easily. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram showing a chlorine dioxide generating apparatus of an embodiment. Figure 2Graph showing the relationship between the amount of chlorine dioxide gas produced and time (Example 1). Figure 3 Graph showing the relationship between the amount of chlorine dioxide gas produced and time (Example 2). Figure 4 Graph showing the relationship between the amount of chlorine dioxide gas produced and time (Example 3). Figure 5 Graph showing the relationship between the amount of chlorine dioxide gas produced and time (Example 4). Figure 6 Graph showing the results of an investigation into how the amount of chlorine dioxide gas produced changes when the amount of buffering substance added is varied to change the pH of the reaction system (Example 5). Figure 7 Schematic diagram of a chlorine dioxide generating device (bag-shaped) according to another embodiment. Figure 8 Graph showing the results of an investigation into how chlorine dioxide gas is produced when the container is made bag-shaped (Example 6). Figure 9 Graph showing the results of an investigation into how chlorine dioxide gas is produced when a gelling agent is added (Example 7). Detailed Description of the Invention

[0046] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In the chlorine dioxide generating device of the present invention, in a solvent in a container, a chlorite, an acidic substance that reacts with the chlorite to produce chlorine dioxide gas, and a buffering substance that is a salt or conjugate base thereof having a buffering effect on the acidic substance are mixed to produce chlorine dioxide gas. Further, in the chlorine dioxide generating method of the present invention, in a solvent in a container, a chlorite, an acidic substance that reacts with the chlorite to produce chlorine dioxide gas, and a buffering substance that is a salt or conjugate base thereof having a buffering effect on the acidic substance are mixed to produce chlorine dioxide gas.

[0047] The reaction between the chlorite and the acidic substance takes place in a solvent in the container. The solvent can be an aqueous solution. At this time, at least either the chlorite or the acidic substance can be made into an aqueous solution state and the two can be mixed in the container to react. In the present embodiment, the case where the chlorite is made into an aqueous chlorite solution will be described. In this case, the acidic substance can be used in any of powder form, solid form, and liquid form. In the present embodiment, the case where the acidic substance in powder form is used will be described.

[0048] Figure 1The chlorine dioxide generation device X is shown, in which an acidic substance B is added to a solvent (aqueous chlorite solution A) in a container 1 having an opening at one end, and the two are mixed and reacted in the container 1 to generate chlorine dioxide gas. The container 1 in the present embodiment only needs to be a container (chlorite accommodation part 12) that can accommodate the aqueous chlorite solution A. The acidic substance B is pre-accommodated in a container (acidic substance accommodation part 13) outside the container 1, etc. When using the chlorine dioxide generation device X, the acidic substance B can be added to the container 1. The opening of the container 1 forms a gas release part 11 that can release gas.

[0049] As the buffering substance C, which is a salt or conjugate base thereof having a buffering effect on the acidic substance B, either a solid form or a liquid form can be used. The buffering substance C can be pre-dissolved or mixed with the aqueous chlorite solution A or the acidic substance B (powder form, solid form, and liquid form) before mixing the aqueous chlorite solution A and the acidic substance B. In the present embodiment, the case where the buffering substance C is dissolved in the aqueous chlorite solution A and then mixed with the acidic substance B will be described.

[0050] As the shape of the container 1, a bottle shape, a tubular shape (test tube shape), a rod shape, a bag shape (pouch shape), a box shape, etc. are exemplified, but it is not limited thereto. In the present embodiment, the case where the container 1 is made into a bottle shape will be described. In addition, regarding the material of the container 1, as long as it has heat resistance and chemical resistance The material of... is not particularly limited. Metals such as glass and stainless steel are particularly preferred. Heat resistance and Resin types such as polypropylene, polyethylene, and Tritan (registered trademark, manufactured by Eastman) with excellent chemical resistance.

[0051] The gas release part 11 can be an open system, but a lid having a breathable structure or a breathable non-permeable member can also be provided. These members can be installed on the opening of the container 1 after adding the acidic substance B to the container 1. As the non-permeable member, for example, a moisture-permeable waterproof sheet (or breathable waterproof sheet) that allows gas, air, and moisture to pass through but does not allow liquid to pass through can be used. The moisture-permeable waterproof sheet can be a microporous membrane (a membrane made of a material with many very small holes) used alone, or a material formed by overlapping and laminating multiple sheets, or a non-porous material that allows gas, air, and moisture (water vapor) to move, or a coated type of material obtained by applying an efficient water repellent treatment to a high-density fabric. As commercially available materials, for example: GORE-TEX (registered trademark), EXEPOL (registered trademark, manufactured by Mitsubishi Chemical Corporation), POLUM (registered trademark, manufactured by Tokuyama Corporation), ENTRANTE (registered trademark, manufactured by Toray Industries, Inc.), TYVEK (registered trademark, manufactured by DuPont), MELFIT (registered trademark, unisel (corporate system), etc. It should be noted that in order to facilitate the installation of the non-permeable component on the container 1, it preferably has heat-sealability (heat fusion property).

[0052] (chlorite) As the chlorite used in the present invention, for example, alkali metal chlorites and alkaline earth metal chlorites can be cited. As alkali metal chlorites, for example, sodium chlorite, potassium chlorite, and lithium chlorite can be cited. As alkaline earth metal chlorites, calcium chlorite, magnesium chlorite, and barium chlorite can be cited. Among them, from the aspect of easy availability, sodium chlorite and potassium chlorite are preferred, and sodium chlorite is most preferred. The above chlorites can be used alone or in combination of two or more.

[0053] The proportion of chlorite in the aqueous chlorite solution is preferably 0.1 to 30% by weight. When it is less than 0.1% by weight, problems such as insufficient chlorite may occur when generating chlorine dioxide gas. Regarding the problem, when it exceeds 30% by weight, It may cause the saturation of chlorite and easily precipitate crystals Considering safety, stability, the generation efficiency of chlorine dioxide gas, etc., 3 to 25% by weight is preferred, and the further preferred range is 3% to 15% by weight.

[0054] (acidic substance) As the acidic substance that can be used in the present invention, it is an acid that reacts with chlorite. Preferably, as long as it is any one of inorganic acids, organic acids, and amphoteric substances, it is not particularly limited. As such acidic substances, for example, inorganic acids can include: phosphoric acid compounds (sodium dihydrogen phosphate or potassium dihydrogen phosphate), acetic acid, sulfuric acid, etc.; organic acids can include: citric acid, malic acid, lactic acid, etc.; amphoteric substances can include: 3-morpholinopropanesulfonic acid, 2-morpholinoethanesulfonic acid, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, etc. Among them, due to excellent storage stability, no generation of corrosive gases, and no concentration change during storage, etc., it is preferred to use phosphoric acid compounds (sodium dihydrogen phosphate or potassium dihydrogen phosphate), acetic acid, and citric acid. Acidic substances can be used alone or in combination of two or more. In addition, the acidic substance can also be in any form of acid anhydride and hydrate.

[0055] The acidic substance can also be in a form included in a porous material. Such porous materials can use, for example, porous materials or calcined aggregates, but are not limited thereto. Examples of the porous material include, for example, porous silica, sepiolite, montmorillonite, diatomaceous earth, talc, zeolite, activated clay, molecular sieve, activated alumina, etc. Among them, porous silica is preferably used in terms of easy availability, excellent porosity (wide porous space), and easy inclusion of acidic substances or chlorites. The specific surface area of these porous silicas, etc. is not particularly limited. As the calcined aggregate, a material obtained by calcining bones, shells, and corals of animals (including mammals, fish, and birds) and making them into crushed flakes, particles, or powders can be used.

[0056] In the state of being contained in such a porous material, the final concentration of the acidic substance can be 30% by weight or less.

[0057] (Buffering substance) As the buffering substance that can be used in the present invention, as long as it is a salt or conjugate base thereof that has a buffering effect on the acidic substance, it is not particularly limited. Substances that meet "a salt or conjugate base thereof that has a buffering effect on the acidic substance" are "salts of acidic substances" or "conjugate bases of acidic substances". The buffering substance can be used alone or in combination of two or more.

[0058] When using a phosphoric acid compound (sodium dihydrogen phosphate or potassium dihydrogen phosphate) as an inorganic acid as the acidic substance, the buffering substance only needs to contain at least any one of potassium phosphate, sodium phosphate, dipotassium hydrogen phosphate, and disodium hydrogen phosphate. In addition, when using acetic acid as an inorganic acid as the acidic substance, the buffering substance only needs to contain at least any one of potassium acetate and sodium acetate. In addition, when using citric acid as an organic acid as the acidic substance, the buffering substance only needs to contain at least any one of potassium citrate and sodium citrate. In addition, the buffering substance can be in any form of acid anhydride and hydrate.

[0059] By dissolving the buffering substance C in the chlorite aqueous solution A, the buffering substance C can be made into a uniform state in the chlorite aqueous solution A. If the acidic substance B is mixed in this state, when the chlorite reacts with the acidic substance to generate chlorine dioxide, the pH of the solvent is less likely to change.

[0060] In the present embodiment, although a scheme of mixing the acidic substance B in a state where the buffering substance C is dissolved in the chlorite aqueous solution A is adopted, a gelling agent can also be added and mixed together with the acidic substance B.

[0061] The gelling agent may be any water-absorbing gelling agent, such as a water-absorbing resin, and is not limited to such a form. Examples of the water-absorbing resin include AQUALIC (registered trademark, manufactured by Nippon Shokubai Co., Ltd.), SUNFLESH (registered trademark, manufactured by Sanyo Chemical Industries, Ltd.), AQUAKEEP (registered trademark, manufactured by Sumitomo Seika Chemicals Co., Ltd.), KI Gel (registered trademark, manufactured by Kuraray Co., Ltd.), etc., but are not limited thereto.

[0062] The timing of adding the gelling agent to container 1 is not limited to the above-mentioned scheme, and the gelling agent may also be added after mixing the acidic substance B in a state where the buffering substance C is dissolved in the chlorite aqueous solution A.

[0063] By adding the gelling agent, the solvent in container 1 can be gelled. Therefore, even if container 1 is tilted, the gelled solvent is not easily spilled from container 1, and thus the operation of the chlorine dioxide generating device X can be easily dropped.

[0064] In the chlorine dioxide generating device X of the present invention, the chlorite and the acidic substance react in the solvent in the container to generate chlorine dioxide gas. At this time, since there is a buffering substance in the solvent, which is a salt or conjugate base having a buffering effect on the acidic substance, the change in the pH of the solvent when chlorine dioxide is generated by the reaction of the chlorite and the acidic substance can be reduced (substantially fixed). Therefore, the generation of chlorine dioxide gas can be stably controlled from the initial stage of the reaction between the chlorite and the acidic substance.

[0065] Therefore, in the case where a buffering substance is added to the reaction system of the chlorite and the acidic substance as in the chlorine dioxide generating device X of the present invention, compared with the case where no buffering substance is added, the concentration of chlorine dioxide gas in the initial stage of the reaction can be suppressed. Therefore, the generation period can be significantly extended while maintaining the generation concentration of chlorine dioxide gas in the initial stage of the reaction.

[0066] The pH of the solvent may be 5 to 7. At this time, the pH of the solvent is the pH value in the mixed state of the sodium chlorite aqueous solution A, the acidic substance B, and the buffering substance C, and can be adjusted by the addition amount of the buffering substance C. If the pH is within this range, stability can be achieved from the initial stage of the reaction Stably control and generate low-concentration chlorine dioxide gas. Preferably, if the pH of the solvent is adjusted to If it is 5.5 to 7, the generation amount of chlorine dioxide gas in the initial stage of the reaction can be further suppressed. More preferably, if the pH of the solvent is adjusted to 6 to 7, the generation amount of chlorine dioxide gas in the initial stage of the reaction can be further controlled.

[0067] The place where the chlorine dioxide generating device X of the present invention is used is not particularly limited, and it can be used in various scenarios, such as general households (living rooms, entrances, bathrooms and kitchens, etc.), industrial uses (factory uses), or medical fields such as hospitals, clinics, sanatoriums, schools, station buildings, public toilets and other public facilities. In addition, it can be used not only in relatively wide spaces such as indoor spaces where people can live, but also in small spaces such as refrigerators, shoe racks, and cars (cars, buses, trains). In this way, the breadth of the space to which the generating device of the present invention can be applied is not particularly limited.

[0068] [Other Implementation Methods 1] Solid (powder) chlorite may be used and the acidic substance may be made into a liquid state, and the embodiment is not limited to the above. In this case, the buffering substance C may be dissolved in the aqueous solution of the acidic substance B in the container 1 and mixed with the chlorite.

[0069] The acidic substance that can be used in this embodiment can be the above-mentioned acidic substance. The concentration of the aqueous solution of the acidic substance can be 30% by weight or less. Example

[0070] [Example 1] As the chlorine dioxide generating device X of the present invention, the following device was prepared: a 23.5 wt% sodium chlorite aqueous solution A (43 mL) was placed in a container 1 (bottle-shaped, 100 mL volume) and 7.7 g of tripotassium phosphate (buffering substance C) was dissolved, and an acidic substance B was placed in a container (acidic substance storage portion 13) outside the container 1. As the acidic substance B, 8.5 g of sodium dihydrogen phosphate (powder) was used.

[0071] Sodium dihydrogen phosphate is added to the container 1, and the chlorite aqueous solution A and sodium dihydrogen phosphate are brought into contact. Chlorine dioxide gas generated immediately after the chlorite aqueous solution A and sodium dihydrogen phosphate are mixed is released to the outside of the container 1 through the gas release part 11, and the object to be treated is subjected to chlorine dioxide treatment for a certain period of time in the fumigation chamber. Figure 2 : is a graph showing the relationship between the amount of generated chlorine dioxide gas and time. As Comparative Example 1, the amount of chlorine dioxide gas generated when the buffering substance C was not added is shown.

[0072] As a result, in Comparative Example 1, a high concentration of chlorine dioxide gas (up to about 3.5 mg per hour) was rapidly produced in large quantities at the initial stage of the reaction (about 100 hours ago), and a low concentration of chlorine dioxide gas (less than 0.5 mg per hour) was produced after about 720 hours (about 1 month). Then, the amount of chlorine dioxide gas produced per hour gradually decreased until about 6 months had passed.

[0073] On the other hand, in Example 1 of the present invention, chlorine dioxide gas is generated at a low concentration (0.3 mg or less per hour) at the initial stage of the reaction, and then, the production amount of chlorine dioxide gas remains at the low concentration at the initial stage of the reaction for a long period (7200 hours, about 10 months). In addition, at the time when about 2500 hours (about 3.5 months) have elapsed since the start of the reaction, the production amount of chlorine dioxide gas per hour exceeds the production amount per hour in Comparative Example 1. Therefore, it can be known that in Example 1 of the present invention, it is possible to stably control and generate chlorine dioxide gas at a low concentration from the initial stage of the reaction. In addition, it can also be known that in Example 1 of the present invention, since the concentration of chlorine dioxide gas at the initial stage of the reaction can be controlled, it is possible to dramatically extend the production period while maintaining the production concentration of chlorine dioxide gas at the initial stage of the reaction, and further extend the life of the chlorine dioxide generating device X.

[0074] 〔Example 2〕 In the chlorine dioxide generating device X used in Example 1, the aqueous chlorite solution (Examples 2-1 to 2-4 of the present invention) was investigated. The results are shown in When the concentration of solution A is variously changed (3 - 25% by weight), how chlorine dioxide gas is generated Figure 3 . As Comparative Examples 2-1 to 2-4, the production amounts of chlorine dioxide gas when the buffering substance C was not added are shown. Figure 4 From the results, it can be known that in Examples 2-1 to 2-4 of the present invention, compared with Comparative Examples 2-1 to 2-4 respectively, it is possible to stably control and generate chlorine dioxide gas at a low concentration from the initial stage of the reaction. Therefore, if the concentration of the aqueous chlorite solution A is 3 to 25% by weight, it is possible to suppress the concentration of chlorine dioxide gas at the initial stage of the reaction, and thus it is possible to dramatically extend the production period while maintaining the production concentration of chlorine dioxide gas at the initial stage of the reaction.

[0075] 〔Example 3〕

[0076] In the chlorine dioxide generating device X used in Example 1, regarding the case where the acidic substance B is potassium dihydrogen phosphate (9.6 g) and the buffering substance C is tripotassium phosphate (7.7 g) (Example 3-1 of the present invention), and the case where the acidic substance B is sodium dihydrogen phosphate (16.5 g) and the buffering substance C is disodium hydrogen phosphate (8.4 g) (Example 3-2 of the present invention), an investigation was made on how to generate chlorine dioxide gas. The results are shown in . As Comparative Examples 3-1 to 3-2, the production amounts of chlorine dioxide gas when the buffering substance C was not added are shown. Figure 5

[0077] ​As a result, it can be seen that, compared with Comparative Examples 3-1 to 3-2 respectively, Examples 3-1 to 3-2 of the present invention can stably control and generate low-concentration chlorine dioxide gas from the initial stage of the reaction. Therefore, it can be known that if at least Acidic Substance B and Buffering Substance C are combined and used as in this embodiment, the concentration of chlorine dioxide gas in the initial stage of the reaction can be inhibited, and thus the generation period can be significantly extended while maintaining the generation concentration of chlorine dioxide gas in the initial stage of the reaction.

[0078] 〔Example 4〕 In the chlorine dioxide generation device X used in Example 1, for the case where Acidic Substance B is acetic acid (2.0 mL) and Buffering Substance C is sodium acetate (25.4 g) (Example 4-1 of the present invention), and the case where Acidic Substance B is citric acid (6.8 g) and Buffering Substance C is trisodium citrate dihydrate (41.6 g) (Example 4-2 of the present invention), an investigation was made on how chlorine dioxide gas is generated. The results are shown in Figure 6 . As Comparative Examples 4-1 to 4-2, the amounts of chlorine dioxide gas generated when Buffering Substance C was not added are shown.

[0079] As a result, it can be seen that, compared with Comparative Examples 4-1 to 4-2 respectively, Examples 4-1 to 4-2 of the present invention can stably control and generate low-concentration chlorine dioxide gas from the initial stage of the reaction. Therefore, it can be known that if at least Acidic Substance B and Buffering Substance C are combined and used as in this embodiment, the concentration of chlorine dioxide gas in the initial stage of the reaction can be inhibited, and thus the generation period can be significantly extended while maintaining the generation concentration of chlorine dioxide gas in the initial stage of the reaction.

[0080] 〔Example 5〕 In the case of the chlorine dioxide generation device X where Acidic Substance B is potassium dihydrogen phosphate and Buffering Substance C is tripotassium phosphate (Example 3-1 of the present invention), an investigation was made on how the amount of chlorine dioxide gas generated changes when the addition amount of tripotassium phosphate as Buffering Substance C is variously changed to change the pH of the reaction system. The results are shown in It can be stably controlled from the initial stage of the reaction . As Comparative Example 5, the amount of chlorine dioxide gas generated when Buffering Substance C was not added is shown.

[0081] The pH of the reaction system of Comparative Example 5 is 4.5. In addition, when the addition amount of tripotassium phosphate as Buffering Substance C is 0.5 g, the pH of the reaction system is 5.0 (Example 5-1 of the present invention), when the addition amount of tripotassium phosphate is 1.7 g, the pH of the reaction system is 5.5 (Example 5-2 of the present invention), when the addition amount of tripotassium phosphate is 3.5 g, the pH of the reaction system is 6.0 (Example 5-3 of the present invention), and when the addition amount of tripotassium phosphate is 7.9 g, the pH of the reaction system is 6.7 - 7.0 (Example 5-4 of the present invention).

[0082] As a result, it can be seen that when tripotassium phosphate, which acts as a buffering substance C, is added, the amount of chlorine dioxide gas generated is 3 mg / hour or less. Compared with Comparative Example 5, in Invention Examples 5-1 to 5-4, And generate low-concentration chlorine dioxide gas. In addition, it is judged Figure 7 it was judged that as the pH of the reaction system increased from 5.0 to 6.7 (about 7.0), the amount of chlorine dioxide gas generated was inhibited. Therefore, it can be seen that if the amount of the buffering substance C added is adjusted to adjust the pH of the reaction system, the amount of chlorine dioxide gas generated can be controlled. In particular, if the pH of the reaction system is adjusted to 5.5 to 7.0, the amount of chlorine dioxide gas generated becomes 2 mg / hour or less, and if the pH of the reaction system is adjusted to 6.0 to 7.0, the amount of chlorine dioxide gas generated becomes 1 mg / hour or less, so that a low-concentration chlorine dioxide gas can be more stably controlled and generated from the initial stage of the reaction.

[0083] It should be noted that in this embodiment, although the results are shown for the case where the acidic substance is a phosphoric acid compound and the buffering substance is a phosphate, the same results (results not shown) were also obtained even when the acidic substance was acetic acid and the buffering substance was acetate, and when the acidic substance was citric acid and the buffering substance was citrate.

[0084] 〔Example 6〕 Although the bottle-shaped container 1 was used in the chlorine dioxide generation device X of Example 1, an investigation was also made on how chlorine dioxide gas was generated when the container 1 was made into a bag shape (bag shape) (Invention Example 7).

[0085] As the bag-shaped container 1, a container ([[]] Figure 8 ) processed into a bag shape (120 mm × 200 mm) when viewed from above was used. The first storage container 10 (100 mm × 150 mm) and the second storage container 20 (80 mm × 100 mm) were accommodated in the bag-shaped container 1 in an overlapping state. The first storage container 10 accommodated an aqueous sodium chlorite solution A and a buffering substance C (tripotassium phosphate) and was composed of an easily destructible layered film 10A; the second storage container 20 accommodated an acidic substance B (sodium dihydrogen phosphate, powder) and was composed of a water-soluble PVA film. At least any one of the front surface and the surface of the container 1 was made into a gas release portion 11, and the gas release portion 11 had air permeability and liquid impermeability.

[0086] An external force is applied by pressing with a finger from the outside of the container 1 to deform it. At this time, the external force applied to the container 1 is transmitted to the easily destructible first storage container 10 to deform the first storage container 10. By increasing the internal pressure therein, the required layer in the laminated film 10A is peeled off, so that the first storage container 10 can be easily destroyed. By destroying the first storage container 10, the sodium chlorite aqueous solution A released into the interior of the container 1 immediately contacts the second storage container 20, and a water-soluble part of the second storage container 20 dissolves. Then, the container 1 is shaken left and right several times to dissolve most of the water-soluble second storage container 20. Thereby, a state in which a sodium chlorite aqueous solution, tripotassium phosphate, and sodium dihydrogen phosphate are mixed is formed, and chlorine dioxide gas is generated.

[0087] The results are shown in Figure 9 . As Comparative Example 7, the amount of chlorine dioxide gas generated when the buffering substance C was not added is shown.

[0088] From the results, it can be seen that, similar to the case of the chlorine dioxide generating device X of Example 1, compared with Comparative Example 7, in Example 7 of the present invention, it is also possible to stably control and generate a low concentration of chlorine dioxide gas (3 mg or less per hour) from the initial stage of the reaction, so that the generation period can be dramatically extended while maintaining the generation concentration state of chlorine dioxide gas at the initial stage of the reaction.

[0089] It should be noted that although in this embodiment, the results are shown for the case where the acidic substance is a phosphoric acid compound and the buffering substance is a phosphate, even when the acidic substance is citric acid and the buffering substance is a citrate, the same results (not shown) are obtained.

[0090] 〔Example 7〕 It was investigated how chlorine dioxide gas was generated (Example 8 of the present invention) when a gelling agent (water-absorbing resin: AQUALIC (manufactured by Nippon Shokubai Co., Ltd.)) was added together with the acidic substance B in the chlorine dioxide generating device X of Example 1. The results are shown in Industrial applicability . As Comparative Example 8, the amount of chlorine dioxide gas generated when the buffering substance C was not added is shown.

[0091] From the results, it can be seen that, similar to the case of the chlorine dioxide generating device X of Example 1 of the present invention, compared with Comparative Example 8, in Example 8 of the present invention, it is also possible to stably control and generate a low concentration of chlorine dioxide gas (0.5 mg or less per hour) from the initial stage of the reaction. Symbol description

[0092] The present invention can be used for a chlorine dioxide generating device and a chlorine dioxide generating method for generating chlorine dioxide gas in a solvent in a container. ​

[0093] X chlorine dioxide generating device A aqueous chlorite solution B acidic substance C buffering substance 1 container.

Claims

1. A chlorine dioxide generating device, in which in a solvent in a container, a chlorite, an acidic substance that reacts with the chlorite to generate chlorine dioxide gas, and a buffering substance that is a salt or conjugate base thereof having a buffering effect on the acidic substance are mixed to generate chlorine dioxide gas.

2. The chlorine dioxide generating device according to claim 1, wherein, the chlorite is sodium chlorite or potassium chlorite, and the acidic substance is any one of inorganic acids, organic acids, and amphiphilic substances.

3. The chlorine dioxide generating device according to claim 1 or 2, wherein, the acidic substance is a phosphoric acid compound.

4. The chlorine dioxide generating device according to any one of claims 1 to 3, wherein, the acidic substance is sodium dihydrogen phosphate or potassium dihydrogen phosphate.

5. The chlorine dioxide generating device according to claim 3 or 4, wherein, the buffering substance is a phosphate.

6. The chlorine dioxide generating device according to claim 5, wherein, the buffering substance contains at least any one of tripotassium phosphate, trisodium phosphate, dipotassium hydrogen phosphate, and disodium hydrogen phosphate.

7. The chlorine dioxide generating device according to claim 1 or 2, wherein, the acidic substance is acetic acid.

8. The chlorine dioxide generating device according to claim 7, wherein, the buffering substance is an acetate.

9. The chlorine dioxide generating device according to claim 7 or 8, wherein, the buffering substance contains at least any one of potassium acetate and sodium acetate.

10. The chlorine dioxide generating device according to claim 1 or 2, wherein, the acidic substance is citric acid.

11. The chlorine dioxide generating device according to claim 10, wherein, the buffering substance is a citrate.

12. The chlorine dioxide generating device according to claim 10 or 11, wherein, the buffering substance contains at least any one of potassium citrate and sodium citrate.

13. The chlorine dioxide generating device according to any one of claims 1 to 12, wherein, the pH of the solvent is 5 to 7.

14. The chlorine dioxide generating device according to any one of claims 1 to 13, wherein, the chlorite is in the form of an aqueous solution of chlorite, and the concentration of the chlorite is 3 to 25% by weight.

15. The chlorine dioxide generating device according to any one of claims 1 to 14, wherein, a gelling agent is added to the solvent in the container.

16. A chlorine dioxide generating method, in which in a solvent in a container, a chlorite, an acidic substance that reacts with the chlorite to generate chlorine dioxide gas, and a buffering substance that is a salt or conjugate base thereof having a buffering effect on the acidic substance are mixed to generate chlorine dioxide gas.

17. The chlorine dioxide generating method according to claim 16, wherein, the acidic substance is mixed in a state where the buffering substance is dissolved in an aqueous solution of chlorite.

18. The chlorine dioxide generating method according to claim 16, wherein, the acidic substance and a gelling agent are mixed in a state where the buffering substance is dissolved in an aqueous solution of chlorite.

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