HK1209971B - Pure chlorine dioxide solution, and gel-like composition and foamable composition each comprising the same - Google Patents

Description

Pure chlorine dioxide liquid, gel composition containing same, and foamable composition

The present invention patent application is a divisional application for an application filed on February 15, 2008, with application number 200880007723.7 and invention name “Pure chlorine dioxide liquid, gel-like composition containing the same and foaming composition”.

Technical Field

The present invention relates to a pure chlorine dioxide liquid, a gel composition containing the same, and a foamable composition.

Background Art

Chlorine dioxide gas is a powerful oxidant, and its oxidizing action is known to be used for sterilization or decomposition of malodorous components. Therefore, chlorine dioxide is used as a bactericide, deodorant, etc. Since chlorine dioxide dissolves 20 times its volume in water to form a yellow-brown aqueous solution, it is desirable to use it in the form of an aqueous solution for ease of handling. However, when an aqueous chlorine dioxide solution comes into contact with air, chlorine dioxide gas is rapidly generated. Therefore, the following scheme has been proposed: by dissolving chlorine dioxide gas in an aqueous solution of sodium _{percarbonate (Na2C2O6 ) to} form an aqueous solution with sodium chlorite ( _NaClO2 ) as the main component and a pH maintained at 9, i.e., a so-called stabilized chlorine dioxide aqueous solution, chlorine dioxide gas is continuously generated while maintaining stability (see Patent Document 1).

However, the stabilized chlorine dioxide aqueous solution is kept at an alkaline pH of 9 to maintain its stability, so sodium chlorite dissociates in the aqueous solution as shown in the following formula (1).

[Chemistry 1]

NaClO ₂ →Na ⁺ +ClO ₂ ^- (1)

Therefore, the generation of free chlorine dioxide gas that exhibits bactericidal and deodorizing effects is extremely small, and there is a problem that the bactericidal and deodorizing effects cannot be fully exerted.

Therefore, it has been proposed to add an irritant or an acid to the stabilized chlorine dioxide aqueous solution immediately before use to adjust the pH to 7 or below to generate chlorine dioxide gas. However, this requires equipment and facilities, which increases costs.

Furthermore, when irritants or acids are pre-added to a stabilized aqueous chlorine dioxide solution, the concentration and duration of chlorine dioxide gas generation depend solely on the concentration of the stabilized aqueous chlorine dioxide solution. Consequently, there is a problem in being unable to control the concentration and duration of chlorine dioxide gas generation depending on the intended use. Furthermore, while this solution can be effectively used for large-scale deodorization of exhaust gas and organic waste generated in industrial sites such as factories, it still presents a problem of being ineffective for simple sterilization or deodorization indoors, in cars, in refrigerators, and the like.

In addition, a proposal has been made to prepare a gel composition by gelling a stabilized chlorine dioxide aqueous solution using a gelling agent such as a culture medium, gelatin, or a superabsorbent resin. However, this gel composition generates very little chlorine dioxide gas, and thus has the problem of not being able to fully exert sterilization and deodorization effects.

Therefore, in order to solve the above problem, a solution of chlorite and an organic acid such as citric acid added to a dissolved chlorine dioxide solution has been proposed to maintain the chlorine dioxide concentration substantially constant over a long period of time (see Patent Document 2).

Patent Document 1: Japanese Patent Application Laid-Open No. 61-181532

Patent Document 2: Japanese Patent No. 3110724

Summary of the Invention

The technology described in Patent Document 2 can maintain a constant chlorine dioxide concentration for a long period of time without causing a sudden increase in gas generation. Even if chlorine dioxide is continuously released as gas, the chlorine dioxide concentration can be maintained within a substantially constant range. However, this is not necessarily sufficient from the perspective of storage stability, and there is room for improvement.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a pure chlorine dioxide solution having further excellent storage stability and capable of maintaining the chlorine dioxide concentration within a substantially constant range for a longer period of time.

The pure chlorine dioxide solution of the present invention is characterized by comprising dissolved chlorine dioxide gas, chlorite, and a pH adjuster, wherein the pH adjuster is an acid (organic acid, inorganic acid) or its salt having a buffering property, wherein the pH of a 5% aqueous solution at 25°C is 2.5 to 6.8. As used herein, "pure chlorine dioxide" means chlorine dioxide present as chlorine dioxide gas, and "pure chlorine dioxide solution" means a solution in which chlorine dioxide is dissolved as chlorine dioxide gas.

Here, the chlorite is preferably sodium chlorite.

Furthermore, the pH adjuster is preferably phosphoric acid or a salt thereof.

Furthermore, the pH adjuster is preferably sodium dihydrogen phosphate, or a mixture of sodium dihydrogen phosphate and disodium hydrogen phosphate.

The gel composition of the present invention is characterized by comprising a pure chlorine dioxide solution and a superabsorbent resin. The pure chlorine dioxide solution comprises dissolved chlorine dioxide gas, chlorite, and a pH adjuster. The pH adjuster is a buffering acid or a salt thereof having a pH of 2.5 to 6.8 at 25°C in a 5% aqueous solution.

Here, the super absorbent resin is preferably a starch-based absorbent resin, a cellulose-based absorbent resin, or a synthetic polymer-based absorbent resin.

Furthermore, the chlorite is preferably sodium chlorite.

Furthermore, the pH adjuster is preferably phosphoric acid or a salt thereof.

Furthermore, the pH adjuster is preferably sodium dihydrogen phosphate, or a mixture of sodium dihydrogen phosphate and disodium hydrogen phosphate.

The foamable composition of the present invention is characterized by comprising a pure chlorine dioxide solution and a foaming agent. The pure chlorine dioxide solution comprises dissolved chlorine dioxide gas, a chlorite, and a pH adjuster. The pH adjuster is a buffering acid or a salt thereof having a pH of 2.5 to 6.8 at 25°C in a 5% aqueous solution.

Here, the foaming agent is preferably composed of a surfactant and a foam stabilizer.

Furthermore, the foaming agent is preferably composed of a surfactant, a foaming stabilizer, and an aerosol propellant.

Furthermore, the chlorite is preferably sodium chlorite.

Furthermore, the pH adjuster is preferably phosphoric acid or a salt thereof.

Furthermore, the pH adjuster is preferably sodium dihydrogen phosphate, or a mixture of sodium dihydrogen phosphate and disodium hydrogen phosphate.

The present invention provides a pure chlorine dioxide liquid that can contain dissolved chlorine dioxide at high concentrations, can freely adjust the concentration range from high to low, and can continuously release chlorine dioxide gas at a substantially constant pharmaceutically effective concentration for a long period of time. Furthermore, a gel composition and a foamable composition containing the same can be provided at low cost. Furthermore, the pure chlorine dioxide liquid, and the gel composition and foamable composition containing the same can be used simply and effectively as an antibacterial/disinfectant, antiviral agent, mildew remover/antifungal agent, and deodorant/deodorant.

According to the present invention, the chlorine dioxide concentration in a chlorine dioxide-containing liquid can be maintained constant over a long period of time. Even if chlorine dioxide is continuously released from the liquid as a gas little by little (or even if chlorine dioxide gas is actively continuously released), excellent storage stability can be achieved, maintaining the chlorine dioxide concentration in the liquid within a substantially constant range. Here, "continuously releasing chlorine dioxide as a gas little by little" means that chlorine dioxide will naturally escape as a gas even when the lid is closed during transportation or storage, for example, while "actively releasing chlorine dioxide gas" means that the gas is released into the gas phase to achieve deodorizing and sterilizing effects.

When phosphoric acid or its salts are used as pH adjusters, storage stability is further improved (storage stability period is further extended) compared to the use of other inorganic acids or organic acids, and temporal fluctuations in liquid properties (pH) during storage are also reduced. Among these, sodium dihydrogen phosphate or a mixture of sodium dihydrogen phosphate and disodium hydrogen phosphate is preferably used from the viewpoint of storage stability.

By selecting sodium dihydrogen phosphate, or a mixture of sodium dihydrogen phosphate and disodium hydrogen phosphate, and using it in combination with sodium chlorite, it is extremely difficult for the sodium chlorite to react excessively to form chlorine dioxide, so the following gas equilibrium state is maintained, that is, the chlorine dioxide lost only due to natural decomposition, diffusion from the lid of the container or the wall of the container is replenished by chlorite ions from the sodium chlorite. In this way, unnecessary consumption of sodium chlorite is suppressed, and sodium chlorite is effectively consumed, so the storage stability is further improved (extended), and the time-dependent variation of the chlorine dioxide concentration during storage is further reduced (not only the concentration is reduced, but the increase in concentration is also suppressed), so it is preferred. In addition, the mechanism of long-term chlorine dioxide replenishment by sodium chlorite in the liquid is also reflected in the space and treatment object where the liquid is applied, sprayed or diffused. Since the application, spraying or diffusion of the above-mentioned liquid provides users with an excellent and long-lasting sterilization and deodorization effect, this can provide great convenience in use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a graph showing the concentration of dissolved chlorine dioxide gas when sodium dihydrogen phosphate is used in a reaction equivalent or more and when citric acid is used in a reaction equivalent or more (the initial concentration is 100 ppm).

FIG2 is a graph showing the concentration of dissolved chlorine dioxide gas when sodium dihydrogen phosphate is used in an amount equivalent to or greater than a reaction amount and when citric acid is used in an amount equivalent to or greater than a reaction amount (the initial concentration is 500 ppm).

DETAILED DESCRIPTION

Hereinafter, an embodiment of the present invention will be described, but the present invention is not limited thereto.

(chlorite)

Examples of chlorites that can be used in the present invention include alkali metal chlorites and alkaline earth metal chlorites. Examples of alkali metal chlorites include sodium chlorite, potassium chlorite, and lithium chlorite, and examples of alkaline earth metal chlorites include calcium chlorite, magnesium chlorite, and barium chlorite. Among these, sodium chlorite and potassium chlorite are preferred, with sodium chlorite being more preferred, not only from the perspective of ease of availability but also from the perspective of sustainability of chlorine dioxide gas generation.

(pH adjuster)

As the pH adjuster that can be used in the present invention, any acid (inorganic acid, organic acid) or its salt having a buffering property of 2.5 to 6.8 in a 5% aqueous solution at 25°C can be used. If the pH is less than 2.5 or exceeds 6.8, the storage stability of the dissolved chlorine dioxide is reduced, and the fluctuation of the liquid properties (pH) of the chlorine dioxide solution during storage becomes larger. In addition, it is preferred to use an acid (inorganic acid, organic acid) or its salt having a buffering property of 3.5 to 6.0 in a 5% aqueous solution at 25°C, and more preferably a pH of 4.0 to 5.5. Specifically, phosphoric acid, boric acid, metaphosphoric acid, pyrophosphoric acid, aminosulfonic acid, acetic acid, etc. can be mentioned. From the viewpoint of obtaining excellent storage stability, inorganic acids or their salts are preferred. In addition, as its salt, for example, sodium dihydrogen phosphate, a mixture of sodium dihydrogen phosphate and disodium hydrogen phosphate can be mentioned. Among them, from the viewpoint of excellent storage stability, being able to suppress the liquid property (pH) change during storage to a minimum, thereby being able to play an excellent bactericidal effect, antiviral effect, antifungal effect, deodorizing effect and the like, it is preferred to use phosphoric acid or its salt, and more preferably sodium dihydrogen phosphate. In addition, one pH adjusting agent can be used alone, or two or more can be used in combination. From the reason of excellent long-term storage stability and little pH change during storage, it is preferred that the pH of the pure chlorine dioxide liquid finally obtained is 4.5 to 6.5, and more preferably 5.5 to 6.0.

(Super absorbent resin)

The pure chlorine dioxide solution of the present invention, containing dissolved chlorine dioxide gas, chlorite, and a pH adjuster (a buffering acid or its salt having a pH of 2.5 to 6.8 (preferably 3.5 to 6.0, more preferably 4.0 to 5.5) in a 5% aqueous solution at 25°C), can be mixed with a superabsorbent resin to form a gel composition. Examples of the super absorbent resin include starch-based super absorbent resins (grafted starch-based super absorbent resins such as starch-acrylonitrile graft copolymers, starch-acrylic acid graft copolymers, starch-styrenesulfonic acid graft copolymers, and starch-vinylsulfonic acid graft copolymers), cellulose-based super absorbent resins (cellulose-acrylonitrile graft copolymers, cellulose-styrenesulfonic acid graft copolymers, cross-linked carboxymethyl cellulose, and other cellulose-based super absorbent resins, materials obtained by phosphate esterification of paper or cloth, materials obtained by carboxymethylation of cloth, and the like), and synthetic polymer-based super absorbent resins (polyvinyl alcohol-based super absorbent resins such as cross-linked polyvinyl alcohol, cross-linked polyacrylic acid salts, polyacrylonitrile-based polymer saponification products, acrylic acid-based super absorbent resins such as polyethylene glycol di(meth)acrylate crosslinks, and cross-linked polyethylene oxide-based super absorbent resins).

Examples of commercially available superabsorbent resins include starch/polyacrylic acid resins [Sanwet (manufactured by Sanyo Chemical Co., Ltd., powder)], cross-linked polyacrylic acid resins [AQUALIC (manufactured by Nippon Shokubai Co., Ltd., powder), ARASORB (manufactured by Arakawa Chemical Co., Ltd., powder), Wondergel (manufactured by Kao Corporation, powder), Aqua-keep (manufactured by Sumitomo Seika Co., Ltd., powder), and DIAWET (manufactured by Mitsubishi Petrochemical Co., Ltd., powder)], isobutylene/maleic acid resins [KI gel (manufactured by Kuraray Co., Ltd., powder)], and polyvinyl alcohol/polyacrylate resins [Sumikagel (manufactured by Sumitomo Chemical Co., Ltd., powder)], and their use does not hinder the present invention.

(foaming agent)

Furthermore, a foamable composition can be prepared by mixing the pure chlorine dioxide solution of the present invention containing dissolved chlorine dioxide gas, chlorite, and a pH adjuster (a buffering acid or its salt having a pH of 2.5 to 6.8 (preferably 3.5 to 6.0, more preferably 4.0 to 5.5) in a 5% aqueous solution at 25°C) with a foaming agent.

The foaming agent (1) is composed of a surfactant and a foaming stabilizer, or (2) is composed of a surfactant, a foaming stabilizer and an aerosol propellant.

Examples of the surfactant include (1) at least one anionic surfactant selected from carboxylates such as polyoxyethylene alkyl ether carboxylic acids, sulfonates such as alkylbenzene sulfonates and alkylnaphthalene sulfonates, sulfate esters such as higher alcohol sulfates, and phosphate esters such as polyoxyethylene alkyl ether phosphates; (2) cationic surfactants such as fatty acid quaternary ammonium salts; (3) carboxybetaine type amphoteric surfactants; (4) nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene glycerol fatty acid esters, polyethylene glycol fatty acid esters, and fatty acid alkanolamides; (5) fluorine-based surfactants; or (6) saponins, etc., but are not limited to these.

Examples of the foaming stabilizer include, but are not limited to, (7) a substance obtained by adding monoethanolamine or diethanolamine to the anionic surfactant; (8) a substance obtained by adding a long-chain alcohol or an alkyl sulfoxide to the nonionic surfactant; or (9) liquid paraffin.

Examples of the aerosol propellant include, but are not limited to, low-toxicity high-pressure gases such as liquefied natural gas (LPG), liquefied butane, and dimethyl ether.

(Preparation Example of Chlorine Dioxide Liquid)

The pure chlorine dioxide solution of the present invention is produced, for example, by (a) dissolving chlorite in water to prepare a 2,000 to 180,000 ppm chlorite aqueous solution, (b) bubbling chlorine dioxide gas into water to dissolve the solution to prepare a 100 to 2,900 ppm chlorine dioxide aqueous solution, and then (c) dissolving chlorite in water to prepare a 2,000 to 180,000 ppm chlorite aqueous solution. A pH adjuster (a buffering acid or its salt having a pH of 2.5 to 6.8 at 25° C. in a 5% aqueous solution) is then dissolved in this solution at a concentration of 0.5 to 100 g per 1,000 ml to prepare a chlorite aqueous solution containing the pH adjuster. Next, 5.0 to 990 ml, preferably 50 to 300 ml, of the aqueous chlorous acid solution (a), 5.0 to 990 ml, preferably 50 to 800 ml, of the aqueous chlorine dioxide solution (b), and 5.0 to 990 ml, preferably 50 to 400 ml, of the aqueous chlorous acid solution (c) containing a pH adjuster are mixed and stirred thoroughly at room temperature to prepare a pure chlorine dioxide solution.

The final pH of the pure chlorine dioxide solution is preferably between 4.5 and 6.5. Outside this range, storage stability is reduced, and the pharmacological activity may fluctuate during storage, or the pharmacological activity may weaken after long-term storage, for example, after two years. The pure chlorine dioxide solution of the present invention preferably has a pH of 5.5 to 6.0.

(Gel composition)

When mixing with a superabsorbent resin to form a gel composition, for example, 50-99% by weight of the pure chlorine dioxide solution prepared as described above is added to 1.0-50% by weight of a superabsorbent resin (powder), and the mixture is thoroughly stirred at room temperature. Such a "gel composition" can be filled into a container having at least one opening (Japanese Patent Application Laid-Open No. 61-40803) for general use. Alternatively, it can be filled into a container formed from paper or nonwoven fabric composed of synthetic fibers, the periphery of which is sealed by thermal fusion of the synthetic fibers or a synthetic resin adhesive. Examples of such synthetic fibers include conventionally known thermoplastic synthetic fibers such as polypropylene fibers, polyester fibers, and polyamide fibers. A container formed from paper or nonwoven fabric composed of such synthetic fibers can prevent clogging due to adhesion of the "gel composition" and can continuously vaporize chlorine dioxide from the "gel composition."

(Foamable composition)

When a foamable composition is prepared by adding a foaming agent, for example, 5.0-20% by weight of a foam stabilizer and 60-95% by weight of a surfactant are added to 1.0-20% by weight of the pure chlorine dioxide solution prepared as described above in a sealed container, and the mixture is thoroughly stirred at room temperature. This "foamable composition" is sealed in a conventional trigger-type foaming container or pump-type foaming container, such as a container for cosmetics, detergents, mildew removers, etc., and is provided for general use.

(Others, usage, purpose, etc.)

The "pure chlorine dioxide liquid" of the present invention is primarily composed of dissolved chlorine dioxide gas, making it highly safe for humans and animals. It can be added to, for example, drinking water, food processing water, and swimming pool water to sterilize (including inactivating viruses, hereinafter the same) and deodorize. Furthermore, it can be used to sterilize vegetables, tableware, and dishcloths by dipping it in an aqueous solution diluted approximately 10-fold with water. Furthermore, it can be diluted approximately 5-fold and sprayed onto kitchen equipment in hotels, restaurants, hospitality businesses, schools, homes, indoor areas, toilets, or automobiles to sterilize and deodorize these items.

Furthermore, the "pure chlorine dioxide liquid" of the present invention can be mixed with a superabsorbent resin to form a gel composition, which can be used for antibacterial and deodorizing purposes in refrigerators, toilets, homes, cars, and the like.

Furthermore, the "pure chlorine dioxide liquid" of the present invention is mixed with a foaming agent to form a foamable composition, which is useful for antibacterial and deodorizing of industrial waste such as diapers used in the field of nursing care, grease traps in restaurant kitchens, new garbage disposal sites, and sludge. In addition, it can also be effectively used for mildew removal of tiles, walls, etc. As the above-mentioned foaming agent, there are (1) a foaming agent composed of a surfactant and a foam stabilizer, and (2) a foaming agent composed of a surfactant, a foam stabilizer and an aerosol propellant. Although the latter has a high production cost, it can form a large amount of bubbles with a small amount of dosage because it uses air. Therefore, it is effective for small objects with high added value such as diapers used in the field of nursing care and grease traps in restaurant kitchens. The foamable composition of the present invention can cover the object to be antibacterial and deodorized over a wide range through the bubbles. In addition, since the bubbles form a layer, antibacterial and deodorizing can be reliably performed, and the durability of the antibacterial and deodorizing effect can be improved.

As described above, the pure chlorine dioxide solution of the present invention and the gel composition and foamable composition containing the same can be used in various applications simply and effectively.

(Example 1)

A chlorine dioxide solution was prepared as follows. Specifically, 680 ml of water was added to 250 ml of water containing 2000 ppm of chlorine dioxide gas. Next, 80 ml of a 25% sodium chlorite solution was added and stirred. Then, sodium dihydrogen phosphate (5% aqueous solution has a pH of 4.1 to 4.5 at 25°C) was added to bring the solution's pH to 5.5 to 6.0 and stirred. This procedure yielded 1000 ml of a chlorine dioxide solution containing dissolved chlorine dioxide gas, sodium chlorite, and sodium dihydrogen phosphate.

(Comparative Example 1)

A chlorine dioxide solution for comparison was prepared in the same manner as in Example 1 except that citric acid (5% aqueous solution has a pH of 1.8 to 2.2 at 25° C.) was used instead of sodium dihydrogen phosphate.

(Example 2)

384 ml of a chlorine dioxide solution prepared in the same manner as in Example 1 was added to 16 g of a cross-linked polyacrylate-based superabsorbent resin [AQUALIC (manufactured by Nippon Shokubai Co., Ltd., powder)] and the mixture was thoroughly stirred at room temperature to obtain 400 g of a light yellow gel composition.

(Example 3)

160 ml of a chlorine dioxide solution prepared in the same manner as in Example 1, 30 ml of a surfactant consisting of sodium alkyl sulfonate, 10 g of liquid paraffin, and 100 g of an aerosol propellant consisting of liquefied butane were placed in a sealed container and thoroughly stirred at room temperature to obtain 300 g of a light yellow foamable composition.

Next, the effects of the present invention will be described as follows: For example, the equilibrium reaction and equilibrium constant when chlorine dioxide gas is dissolved in water are represented by the following formula (2) and formula (3), respectively.

According to the above formula (2) and formula (3), chlorine dioxide gas (ClO ₂ ) exists overwhelmingly as dissolved chlorine dioxide at room temperature.

When sodium chlorite and sodium dihydrogen phosphate are added as a chlorite and a pH adjuster (a 5% aqueous solution having a buffering pH of 2.5 to 6.8 at 25°C), respectively, to the aqueous solution containing dissolved chlorine dioxide, the pH of the solution is maintained at an acidic level and rapid pH changes are suppressed. Therefore, due to the presence of sodium dihydrogen phosphate, sodium chlorite is ionized in water to produce chlorous acid as shown in the following formula (4).

NaClO ₂ +H ⁺ →Na ⁺ +HClO ₂ (4)

Thus, when chlorous acid is generated, the reaction proceeds to the left in the equilibrium state of equation (2), i.e., the reverse reaction proceeds. Therefore, when sodium chlorite and sodium dihydrogen phosphate are present in the aqueous solution of chlorine dioxide gas, the maximum concentration of dissolved chlorine dioxide is 2900 ppm or less, and the concentration of dissolved chlorine dioxide gas increases. Therefore, the "pure chlorine dioxide solution" of the present invention can contain dissolved chlorine dioxide at a high concentration.

Furthermore, among the four compounds in formula (2), _ClO2 is the most reactive and easily volatilizes from an aqueous solution (boiling point 11°C, vapor pressure 500 Torr (0°C)). Therefore, the reaction in formula (2) proceeds in the left direction, that is, the reverse reaction proceeds. Therefore, the reduction of dissolved chlorine dioxide is often supplemented by chlorous acid derived from sodium chlorite.

Furthermore, sodium dihydrogen phosphate not only makes the pH of the pure chlorine dioxide solution of the present invention acidic, but also acts as a buffer to suppress rapid pH fluctuations, thereby suppressing the rapid change from sodium chlorite to chlorous acid in the above formula (4), preventing the rapid increase in the release of dissolved chlorine dioxide in formula (2), and suppressing the reduction in the sustainability of the antibacterial and deodorizing effects of the solution.

Therefore, the "pure chlorine dioxide solution" of the present invention can contain high concentrations of dissolved chlorine dioxide, freely adjustable within a range of concentrations from high to low. Furthermore, even when the dissolved chlorine dioxide is released, it can be replenished to maintain a substantially constant, effective concentration of chlorine dioxide gas for extended periods of time. This prevents a sudden increase in the release of dissolved chlorine dioxide, thereby suppressing a decrease in the sustained effectiveness of the solution for antibacterial and deodorizing effects. These superior effects of the "pure chlorine dioxide solution" of the present invention are also exhibited in the "gel composition" and "foamable composition" of the present invention.

Furthermore, the "pure chlorine dioxide liquid" of the present invention has dissolved chlorine dioxide gas as its main component, and therefore is extremely effective in preventing and eliminating bacteria, for example, Escherichia coli (O-157), Salmonella, Staphylococcus aureus, and Clostridium botulinum; in preventing and eliminating viruses, such as influenza virus, avian influenza virus, norovirus (feline calicivirus), human papillomavirus, coxsackievirus, HIV, hepatitis B virus, canine parvovirus, rotavirus, HHV-1 (herpes simplex virus type 1 (HSV-1)), HHV-2 (herpes simplex virus type 2 (HSV-2)), HHV-3 (varicella-zoster virus (VZV)), and HHV-5 (cytomegalovirus (CMV)); in preventing and eliminating various molds; and in preventing and eliminating odors, such as cigarette odor, body odor, and various food odors.

Conventional "stabilized chlorine dioxide" is an aqueous solution primarily composed of sodium chlorite ( _NaClO₂ ) maintained at a pH of 9 (alkaline). _NaClO₂ dissociates as shown in formula (1) ^. As described above, _ClO₂ forms hydrogen bonds with water molecules in the aqueous solution. Consequently, the volatilization of free chlorine dioxide gas ( _ClO₂ ) is minimal, resulting in a very weak oxidizing power. In this specification, "stabilized chlorine dioxide" refers to chlorine dioxide in the form of a modified form of sodium chlorite. In contrast, the oxidizing power of the "pure chlorine dioxide solution" of the present invention is very strong, as it originates from _ClO₂ dissolved in water. Therefore, the antibacterial activity of the "pure chlorine dioxide liquid" of the present invention is 360 times more potent than that of conventional "stabilized chlorine dioxide." Furthermore, the antibacterial concentration of the "pure chlorine dioxide liquid" of the present invention is 0.1 ppm or higher, while the antibacterial concentration of conventional "stabilized chlorine dioxide" is 300 ppm or higher. Furthermore, the probability of chlorine dioxide gas generated by the "pure chlorine dioxide liquid" of the present invention contacting bacteria is significantly superior to that generated by conventional "stabilized chlorine dioxide."

Conventional "stabilized chlorine dioxide" solutions are often temporarily increased by adding an irritant or acid to an aqueous solution immediately before use to maintain a pH below 7. This has been previously discussed. However, the "pure chlorine dioxide solution" of the present invention can contain dissolved chlorine dioxide at a high concentration, even without the addition of such irritants or acids. The concentration can be freely adjusted from high to low, and chlorine dioxide gas can be continuously released at a substantially constant effective concentration for a long period of time, thereby maintaining high efficacy. Furthermore, the present invention exhibits superior storage stability compared to previously proposed technologies (such as those described in Patent Gazette No. 3110724), enabling long-term maintenance of high efficacy. The pure chlorine dioxide solution of the present invention, as well as gel compositions and foamable compositions containing the same, can be used simply and effectively as antibacterial and disinfectant agents, antiviral agents, mold removers and mildew inhibitors, and deodorizers and deodorizers.

(Stabilization test)

The chlorine dioxide solution obtained in Example 1 was diluted using a conventional method to prepare chlorine dioxide solutions with concentrations of 100 ppm and 500 ppm. Similarly, the chlorine dioxide solution obtained in Comparative Example 1 was adjusted to chlorine dioxide concentrations of 100 ppm and 500 ppm.

To investigate the storage stability of these solutions, the time-dependent changes in dissolved chlorine dioxide concentration (ppm) were measured. Stabilization tests were also conducted using an accelerated test (measurement temperature: 54°C, 14 days equivalent to one year at room temperature) according to conventional methods. The storage stability results are shown in the following table and figure (comparative data when sodium dihydrogen phosphate (sodium phosphate) was added in a reaction equivalent or greater, and when citric acid (citric acid) was added in a reaction equivalent or greater).

[Table 1]

※54℃ accelerated test (14 days is equivalent to 1 year at room temperature)

[Table 2]

※54℃ accelerated test (14 days is equivalent to 1 year at room temperature)

As can be seen from the above [Table] and the other [Figure], the use of a pH adjuster having a pH of 2.5 to 6.8 at 25°C in a 5% aqueous solution significantly improves the storage stability of the chlorine dioxide solution compared to the use of an acid with buffering properties having a pH outside the range of 2.5 to 6.8, and also minimizes fluctuations in the liquid properties (pH) during storage.

Industrial applicability

The present invention can be preferably used as an antibacterial/antibacterial agent, an antiviral agent, a mildew remover/antifungal agent, and a deodorant/deodorant.

Claims (6)

1. A method for preparing a gel-like composition, characterized in that the gel-like composition contains a chlorine dioxide liquid agent and a superabsorbent resin, wherein the chlorine dioxide liquid agent comprises dissolved chlorine dioxide gas, chlorite, and a pH adjuster. The preparation method includes the following steps: (1) The steps for preparing the following solutions (A) and (B) independently, respectively. (A) A solution containing chlorine dioxide gas. (B) A solution containing chlorite. (2) The step of preparing a chlorine dioxide liquid solution with a pH of 4.5 to 6.5 by mixing the above solution (A), the above solution (B), and phosphate or its salt as a pH adjuster, and, (3) The process of mixing the chlorine dioxide liquid obtained in step (2) with the superabsorbent resin. 2. The preparation method according to claim 1, wherein the solution (A) in step (1) is a solution containing chlorine dioxide gas at a concentration of 100 to 2900 ppm. 3. The preparation method according to claim 2, wherein the solution (B) in step (1) is a solution containing chlorite at a concentration of 2000 to 180000 ppm. 4. The preparation method according to any one of claims 1 to 3, wherein the superabsorbent resin is a starch-based superabsorbent resin, a cellulose-based superabsorbent resin, or a synthetic polymer-based superabsorbent resin. 5. The preparation method according to any one of claims 1 to 3, wherein the chlorite is sodium chlorite. 6. The preparation method according to any one of claims 1 to 3, wherein the pH adjuster is sodium dihydrogen phosphate, or a mixture of sodium dihydrogen phosphate and disodium hydrogen phosphate.