JP7717390B2 - bactericidal composition - Google Patents

Description

The present invention relates to a disinfectant composition. Specifically, it relates to a disinfectant composition based on weakly acidic hypochlorous acid water with enhanced rust prevention effects.

The form of hypochlorous acid in an aqueous solution changes depending on the pH. Specifically, in the weakly acidic region of about pH 3 to 6, most of it exists as molecular hypochlorous acid (HClO), while in the basic region of pH 9 or higher, it is predominantly present as dissociated hypochlorous acid ions (OCl ⁻ ). In the strongly acidic region (for example, below pH 3), the generation of chlorine molecules (Cl ₂ ) becomes predominant as the pH decreases. Among these forms, molecular hypochlorous acid (HClO) has an extremely high bactericidal effect, and its bactericidal effect is said to be about 80 times that of ionic hypochlorous acid (OCl ⁻ ). Weakly acidic hypochlorous acid water with a pH of 3 to 6, which contains a large amount of molecular hypochlorous acid with such a high bactericidal effect, is also relatively safe for the human body and is therefore used as a disinfectant or bactericide in various fields such as medicine, dentistry, agriculture, and food processing (see Patent Documents 1, 4, and 5).

However, chlorine-based disinfectants and germicides are known to be corrosive to metals, and the same is true for weakly acidic hypochlorous acid. Furthermore, compared to aqueous solutions of hypochlorite salts such as sodium hypochlorite, which have a high pH, weakly acidic hypochlorous acid water is more corrosive, corroding metals at lower concentrations in a shorter period of time. To address this issue, germicidal cleaners containing rust inhibitors made from organic acids and their salts or inorganic rust inhibitors, as well as germicidal cleaners containing buffering agents, have been proposed.

For example, Patent Document 2 discloses a disinfectant composition containing "(A) one or more compounds selected from hypochlorous acid and alkali metal hypochlorite salts; (B) one or more compounds selected from polyhydric alcohol derivative surfactants, cationic surfactants, and amphoteric surfactants; (C) one or more compounds selected from organic acids and their salts; and (D) a rust inhibitor," and states that the rust inhibitor is one or more compounds selected from phosphoric acid, polyphosphoric acid, phosphonic acid, and their salts.

Patent document 3 also describes how metal corrosion can be effectively inhibited by adding a buffering agent to a hypochlorous acid aqueous solution, which has traditionally been used as a disinfectant, and states that organic acids and salts of organic acids are preferred as buffering agents.

Japanese Patent Application Laid-Open No. 2019-202907 Japanese Patent Application Laid-Open No. 2002-161011 International Publication No. 2006/057311 JP 2000-109887 A JP 2010-138101 Public Relations

The inorganic rust inhibitors of phosphoric acid and polyphosphoric acid used in Patent Document 2 exert their rust-preventing effect by depositing metal salts on the metal surface and forming a film. However, when using such rust inhibitors, not only are there problems with unevenness in the film causing partial rusting, and problems with deposits remaining on the metal surface even after rinsing with water, but there are also problems with long-term storage because organic acids are quickly oxidized by hypochlorous acid and the hypochlorous acid is reduced, deactivating their bactericidal ability. Furthermore, even if they are mixed immediately before use, their bactericidal ability decreases upon use. Furthermore, in Patent Document 3, the buffering agents preferably used to impart rust-preventing effects are organic acids and organic acid salts, which have the same problems as those mentioned above.

The present invention therefore aims to provide a mildly acidic hypochlorous acid water-based disinfectant composition that is less corrosive to metals (has anti-rust effects) and does not contain any components that reduce its disinfecting ability during storage or that tend to remain on the surface of the substance to be disinfected after use.

The present invention solves the above-mentioned problems, and a first aspect of the present invention is a disinfectant composition characterized by comprising a weakly acidic hypochlorous acid aqueous solution having a pH of 3.0 or more and 7.0 or less in which (A) molecular hypochlorous acid and (B) a nonionic surfactant are dissolved, and which does not contain or is substantially free of (C) organic acids and salts thereof, and (D) ionic surfactants.

In the disinfectant composition of the first aspect of the present invention (hereinafter also referred to as the "disinfectant composition of the present invention"), the nonionic surfactant (B) is preferably a compound that does not have a carbon-carbon multiple bond in the molecule, and is preferably at least one compound selected from the group consisting of polyglycerol fatty acid esters and fluorine-based nonionic surfactants.

Furthermore, when the effective chlorine concentration (ppm by mass) contained in the weakly acidic hypochlorous acid aqueous solution is represented by _CA , the total concentration (ppm by mass) of the (B) nonionic surfactant contained in the weakly acidic hypochlorous acid aqueous solution is represented by _CB , the total concentration (ppm by mass) of the (C) organic acid and its salt that may be contained in the weakly acidic hypochlorous acid aqueous solution is represented by _CC , the total concentration (ppm by mass) of the (D) ionic surfactant that may be contained in the weakly acidic hypochlorous acid aqueous solution is represented by _CD , and the total concentration (ppm by mass) of metal ions that may be contained in the weakly acidic hypochlorous acid aqueous solution is represented by _CE , it is preferable that at least all of the conditions represented by the following formulas (1) to (3) are satisfied, and it is more preferable that all of the conditions represented by the following formulas (1) to (4) are satisfied.
0.5≦C _B /C _A ≦1000 (1)
C _C /C _A <0.05 (2)
C _D /C _A <0.05 (3)
C _E /C _A ≦0.35 (4).

A second aspect of the present invention is a germicidal cleaner characterized by containing the germicidal composition of the present invention. This germicidal cleaner (hereinafter also referred to as the "germicidal cleaner of the present invention") is preferably a germicidal cleaner for cleaning and/or sterilizing an article at least a portion of whose surface is formed of metal.

A third aspect of the present invention is a two-component kit for preparing the disinfectant composition of the present invention by mixing the first and second liquids in a predetermined ratio, the kit comprising a first liquid comprising a weakly acidic aqueous solution of hypochlorous acid that does not contain the component (B), and a second liquid comprising an aqueous solution of the component (B). The kit is characterized in that, when the ratio of the mass of the second liquid to the mass of the first liquid mixed in the predetermined ratio is defined as the (mass of second liquid/mass of first liquid) ratio: X, X is 0.01 or greater and 10 or less, the available chlorine concentration in the weakly acidic aqueous solution of hypochlorous acid of the first liquid is equivalent to the available chlorine concentration of the disinfectant composition to be prepared multiplied by (1 + X), and the concentration of the component (B) in the aqueous solution of the second liquid is equivalent to the concentration of the component (B) in the disinfectant composition to be prepared multiplied by {(1 + X)/X}.

A fourth aspect of the present invention is a two-component kit for preparing the disinfectant composition of the present invention by mixing the first and second liquids with externally supplied water in a predetermined ratio, the kit comprising a first liquid comprising a weakly acidic aqueous solution of hypochlorous acid that does not contain the component (B), and a second liquid comprising an aqueous solution of the component (B). The kit is configured such that the mass ratio of the second liquid and the mass ratio of the water to the mass of the first liquid to be mixed in the predetermined ratio are (mass of second liquid/mass of first liquid): Y and (mass of water/mass of first liquid): Y, respectively. The two-component kit is characterized in that, when Z is Y, Y is 0.01 or more and 2 or less and Z is 2 or more and 50 or less, the effective chlorine concentration in the weakly acidic hypochlorous acid aqueous solution of the first liquid is equivalent to the effective chlorine concentration of the disinfectant composition, which is the object of preparation, multiplied by (1 + Y + Z), and the concentration of the component (B) in the aqueous solution of the second liquid is equivalent to the concentration of the component (B) in the disinfectant composition, which is the object of preparation, multiplied by {(1 + Y + Z)/Y}.

The disinfectant composition of the present invention uses molecular hypochlorous acid (HClO) as its active ingredient, and thus has the same high disinfecting properties as conventional disinfectant compositions made from weakly acidic aqueous hypochlorous acid solutions. Combined with its pH, it also has the advantage of being relatively safe for humans. Furthermore, despite being a chlorine-based composition, it has the excellent advantages of low metal corrosivity (does not easily cause metals to rust), can be stored stably, and does not leave deposits on the surface of the substance to be disinfected after use.

The disinfectant composition of the present invention was developed based on the discovery, made by the inventors, that "adding a nonionic surfactant to weakly acidic hypochlorous acid water can impart a rust-preventing effect." Further investigation based on this discovery revealed that nonionic surfactants not only have a rust-preventing effect, but also have the unique property of being less likely to decompose molecular hypochlorous acid than ionic surfactants. Therefore, by incorporating a nonionic surfactant and being substantially free of organic acids, their salts, and ionic surfactants, which have traditionally been used as rust inhibitors, the disinfectant composition of the present invention has succeeded in achieving this effect.

The inventors were the first to confirm that nonionic surfactants function as rust inhibitors in weakly acidic hypochlorous acid aqueous solutions, and to the best of their knowledge, there have been no other reported examples demonstrating this. There are several known techniques for adding surfactants to basic hypochlorite aqueous solutions such as sodium hypochlorite aqueous solutions, or to aqueous solutions made neutral to acidic by adding a buffer, but the purpose of adding surfactants to such systems is not to achieve rust prevention.

For example, Patent Document 4 describes a "food disinfectant cleaning composition comprising a first agent containing a polyglycerol fatty acid ester and a pH adjuster, a second agent primarily composed of sodium hypochlorite or ozone, and water, the pH of which is 3 to 7 upon mixing." The polyglycerol fatty acid ester is a nonionic surfactant. However, its addition is said to be intended to enhance cleaning effectiveness. Furthermore, as can be seen from the fact that the disinfectant cleaning composition is stored in two separate components, the composition contains a pH adjuster such as phosphoric acid, which reduces storage stability when the two components are mixed to form a single solution, raising concerns about the aforementioned deposits.

Furthermore, Patent Document 5 describes an "antibacterial composition comprising a specific alcohol compound (A), a surfactant (B), and one or more compounds (C) selected from hypochlorous acid, hypochlorites, and compounds that release hypochlorous acid in water, wherein the weight ratio of (A) to (B): (A)/(B) is 2 or less." However, here too, the purpose of adding surfactants and other additives is to provide antibacterial activity against fungi that adhere to the fibers of textile products or to relatively intricate areas of products with hard surfaces. Patent Document 5 also states that the preferred pH of the antibacterial composition is 6 to 14, and even 8 to 13.5. Specifically, the solution used is a sodium hypochlorite aqueous solution. To obtain a weakly acidic hypochlorous acid aqueous solution, the pH must be adjusted by adding a buffer (which may be added). For this reason, weakly acidic hypochlorous acid aqueous solutions are considered to have the same problems as the germicidal cleaner composition of Patent Document 4.

Furthermore, in the disinfectant composition described in Patent Document 2, the surfactant is added to prevent a decrease in disinfecting activity due to the addition of a rust inhibitor, and it is assumed that the composition will be used in combination with a rust inhibitor.

In contrast to these conventional techniques, the disinfectant composition of the present invention has the excellent feature of exhibiting a rust-preventing effect without substantially containing organic acids, their salts, or ionic surfactants, and can therefore be suitably used, for example, as a disinfectant cleaner for cleaning and/or sterilizing articles at least a portion of whose surface is made of metal.
The bactericidal composition and the bactericidal cleaning agent of the present invention will be described in more detail below, focusing on the components contained therein. In this specification, the expression x to y means a range of x or more and y or less, and when only y has a unit, this means that x also has the same unit.

1. Relationship between pH of weakly acidic hypochlorous acid water and (A) molecular hypochlorous acid, and effective chlorine concentration As mentioned above, the form of available chlorine in hypochlorous acid water depends on the pH of the aqueous solution. In the weakly acidic hypochlorous acid water constituting the disinfectant composition of the present invention, the pH is set to 3 to 7, preferably 3.5 to 5.5, so that most of the available chlorine in the hypochlorous acid water exists as (A) molecular hypochlorous acid, thereby providing high disinfection properties, and from the viewpoint of safety.

From the viewpoint of bactericidal effect and low corrosiveness to metals (rust prevention effect), the effective chlorine concentration in the bactericidal composition of the present invention is preferably 2 ppm to 2000 ppm. If the effective chlorine concentration is less than 2 ppm, it tends to be difficult to achieve a sufficient bactericidal effect, while if it exceeds 2000 ppm, the bactericidal effect saturates and it becomes difficult to achieve the rust prevention effect of the nonionic surfactant (B). From the viewpoint of bactericidal efficiency, the effective chlorine concentration is preferably 10 ppm to 1500 ppm, and more preferably 30 to 1000 ppm.

The term "available chlorine concentration (ppm by mass)" refers to the total chlorine-equivalent concentration of chlorine molecules, oxidizing chlorine compounds (e.g., molecular hypochlorous acid), and oxidizing chlorine-atom-containing ions (e.g., ionic hypochlorous acid) dissolved in an aqueous solution. More specifically, it refers to the concentration obtained by summing the mass-based chlorine concentrations of each component after converting them to mass-based chlorine concentrations. In a weakly acidic aqueous solution of metal hypochlorite, in the pH range where hypochlorous acid is present almost entirely in molecular form, the available chlorine concentration essentially refers to the available chlorine concentration derived from molecular hypochlorous acid. In this invention, the available chlorine concentration is measured by absorptiometry using an iodine reagent, and can be measured, for example, using the Available Chlorine Concentration Measurement Kit AQ-202 (Shibata Scientific Co., Ltd.).

Such weakly acidic hypochlorous acid water can be produced, for example, by the electrolysis method, in which a sodium chloride aqueous solution is electrolyzed; the hydrochloric acid method, in which hydrochloric acid is added to a basic hypochlorite aqueous solution; or the ion exchange method, in which a raw aqueous solution consisting of a hypochlorite aqueous solution is treated with an ion exchange resin.

2. (B) Nonionic Surfactant The (B) nonionic surfactant contained in the weakly acidic hypochlorous acid aqueous solution constituting the disinfectant composition of the present invention is not particularly limited as long as it has a hydrophilic portion and a lipophilic portion in the molecule and is a surfactant consisting of a compound that does not become ionic when dissolved in water, and for example, polyglycerin fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, fatty acid polyethylene glycol, fatty acid polyoxyethylene sorbitan, polyglycerin alkyl ether, polyoxyethylene alkyl ether, fluorine-based nonionic surfactant, etc. can be used. In terms of the stability of the substance, it is preferable to use polyglycerin fatty acid ester or fluorine-based nonionic surfactant, and among them, it is more preferable to use polyglycerin fatty acid ester due to its ease of availability.

Furthermore, from the viewpoint of the storage stability of the antiseptic composition of the present invention, it is particularly preferable to use a nonionic surfactant that does not contain a carbon-carbon multiple bond in the molecule. Such nonionic surfactants that do not contain a carbon-carbon multiple bond in the molecule are commercially available, and examples of suitable surfactants that can be used include polyglyceryl-10 laurate (C ₁₂ H ₂₄ O ₂ —(C ₃ H ₆ O ₂ ) ₁₀ ), polyglyceryl-4 lauryl ether (C ₁₂ H ₂₆ O—(C ₃ H ₆ O ₂ ) ₄ ), polyoxyethylene (5) lauryl ether, and perfluoroalkyl group-containing nonionic surfactants.

The amount of nonionic surfactant (B) contained in the weakly acidic hypochlorous acid aqueous solution is typically 30 ppm by mass to 15% by mass, based on the mass of the weakly acidic hypochlorous acid aqueous solution. However, from the perspective of rust prevention effect and ease of removal by rinsing with water, it is preferably 50 ppm by mass to 1.5% by mass, and more preferably 100 ppm by mass to 1,500 ppm by mass.

Furthermore, from the viewpoint of more effectively exerting the rust prevention effect and the bactericidal effect, when the effective chlorine concentration (ppm by mass) contained in the weakly acidic hypochlorous acid aqueous solution is represented by _CA and the total concentration (ppm by mass) of the (B) nonionic surfactant is represented by _CB , the ratio of the two, _CB / _CA , preferably satisfies the relationship 0.5≦ _CB / _CA ≦1000, and more preferably satisfies the relationship 0.7≦ _CB / _CA ≦900, particularly 1.0≦ _CB / _CA ≦800.

3. (C) Organic Acids and Their Salts, and (D) Ionic Surfactants As described above, in conventional bactericidal compositions based on a weakly acidic hypochlorous acid aqueous solution or a basic hypochlorite aqueous solution, (C) organic acids and their salts have sometimes been added as rust inhibitors or buffers. Furthermore, surfactants, including (D) ionic surfactants, have sometimes been added together with the rust inhibitors and buffers to enhance cleaning properties.

In contrast, in the present invention, in order to obtain the above-mentioned effect, the weakly acidic hypochlorous acid aqueous solution constituting the disinfectant composition of the present invention must be substantially free of (C) organic acids and their salts, and (D) ionic surfactants.

Here, "substantially free" means that it is not contained at all or is not actively (or intentionally) added, but its unavoidable inclusion is permitted within a range that does not adversely affect storage stability, etc. The upper limit of the allowable amount depends on the effective chlorine concentration: C _A , and is usually a concentration that satisfies the following formulas (2) and (3) when expressed as the ratio of each concentration to the effective chlorine concentration.
C _C /C _A <0.05 (2)
C _D /C _A <0.05 (3)
In the above formula, C _C represents the total concentration (ppm by mass) of the (C) organic acid and its salt that may be contained in the weakly acidic aqueous hypochlorous acid solution, and C _D represents the total concentration (ppm by mass) of the (D) ionic surfactant that may be contained in the weakly acidic aqueous hypochlorous acid solution.

Furthermore, the absolute concentrations of (C) and (D) are each preferably 10 mass ppm or less, more preferably 5 mass ppm or less, and most preferably 1 mass ppm or less, based on the total mass of the weakly acidic hypochlorous acid aqueous solution.

(C) Examples of organic acids and their salts that are not substantially contained include citric acid, malonic acid, glutaric acid, adipic acid, sebacic acid, fumaric acid, maleic acid, and their salts.

In addition, examples of (D) ionic surfactants that are substantially not contained include anionic surfactants such as carboxylic acid types such as aliphatic carboxylates and polyoxyethylene alkyl ether carboxylates, sulfonic acid types such as dialkyl sulfosuccinates and alkanesulfonates, sulfate ester types such as alkyl sulfates and fat sulfate esters, and phosphate ester types such as alkyl phosphates and polyoxyethylene alkyl ether phosphates; cationic surfactants such as alkylamine salt types such as monoalkylamine salts and dialkylamine salts, and quaternary ammonium salt types such as alkylbenzalkonium chloride and alkyltrimethylammonium chloride; and amphoteric surfactants such as alkylbetaine and 2-alkylimidazoline derivatives.

4. Metal Ions Generally, molecular hypochlorous acid in an aqueous solution is represented by the following formula:
2HClO → 2HCl + O ₂ and/or 3HClO → 2HCl + HClO ₃
and rapid reductive decomposition when it comes into contact with organic matter that has reducing properties, including fungi, which are the targets of sterilization:
HClO → HCl + (O)
It is known to disappear due to

Incidentally, when a weakly acidic hypochlorous acid aqueous solution is produced using a hypochlorite such as sodium hypochlorite as a raw material, metal ions derived from the raw material are often contained in the weakly acidic hypochlorous acid aqueous solution. For example, when an acid or buffer is added to a sodium hypochlorite aqueous solution to make it weakly acidic, not only will the metal ions derived from the raw material be contained as they are, but also metal ions derived from the buffer will be contained. Furthermore, even when produced by an ion exchange method using a cation exchange resin to convert metal ions derived from the raw material into hydrogen ions (H ⁺ ) and remove the metal ions, a considerable amount of metal ions will be contained depending on the conditions. It is known that such metal ions rapidly accelerate the autolysis reaction when the metal ion concentration exceeds a certain ratio relative to the available chlorine concentration. That is, Patent Document 1 describes that, for a weakly acidic hypochlorous acid aqueous solution at a liquid temperature of 5 to 40°C, when the total concentration (ppm by mass) of metal ions contained therein is expressed as C _E , the ratio of C _E /C _A to the available chlorine concentration C _A becomes 0.35 or more. Therefore, in the weakly acidic aqueous hypochlorous acid solution constituting the disinfectant composition of the present invention, it is preferable that the C _E /C _A satisfies the condition shown in the following formula (4), and it is particularly preferable that it satisfies the condition shown in the following formula (4').
C _E /C _A ≦0.35 (4)
C _E /C _A ≦0.25 (4′).

In order to obtain a weakly acidic hypochlorous acid aqueous solution that satisfies the above conditions, for example, the method described in Patent Document 1 can be adopted. That is, the method includes: an ion exchange step of mixing a raw material aqueous solution consisting of an aqueous solution of a metal salt of hypochlorous acid with a weakly acidic ion exchange resin to carry out ion exchange between metal ions and hydrogen ions, thereby generating molecular hypochlorous acid dissolved in the mixed solution; and a separation step of separating the weakly acidic ion exchange resin from the mixed solution after the ion exchange step to obtain a target aqueous solution consisting of an aqueous solution in which molecular hypochlorous acid is dissolved; In the ion exchange step, the amount ratio of the raw material aqueous solution and the weakly acidic ion exchange resin to be mixed is such that the ratio of the total ion exchange equivalent (E _IE ) of the weakly acidic ion exchange resin to the total chemical equivalent (E _MI ) of the metal ions in the raw material aqueous solution: (E _MI /E _IE ) is 0.05 or more and 0.5 or less, and the liquid temperature during mixing is 5 ° C or more and 40 ° C or less, and the mixing time is 10 minutes or more and 120 minutes or less.

The weakly acidic aqueous hypochlorous acid solution constituting the disinfectant composition of the present invention may contain, as necessary, metal ions exhibiting antibacterial properties such as silver ions, zinc ions, and copper ions, or foaming agents consisting of carbonates, bicarbonates, and double salts of bicarbonates and carbonates, which serve as metal ion sources. Even in such cases, it is preferable that the C _E /C _A ratio satisfies the condition represented by the formula (4), particularly the formula (4').

5. Regarding the preparation method and use of the disinfectant composition of the present invention, the disinfectant composition of the present invention may be prepared by first mixing all components to a predetermined concentration to prepare the weakly acidic hypochlorous acid aqueous solution, which may then be used as the disinfectant composition as is. Alternatively, a weakly acidic hypochlorous acid aqueous solution several to several tens of times stronger than the concentration at the time of use may be prepared, and this may be diluted with water to obtain a weakly acidic hypochlorous acid aqueous solution of a predetermined concentration, which may then be used as the disinfectant composition of the present invention. However, in the latter case, if the concentration of each component is too high, the storage stability tends to decrease when stored for a long period of time. For this reason, when diluted for use, it is preferable to prepare a two-component kit (also a kit for preparing the disinfectant cleaner of the present invention) shown in (1) or (2) below for long-term storage, and either mix the two solutions (in the case of (1)) or mix the two solutions and then further dilute with a predetermined amount of water (in the case of (2)) to prepare a disinfectant composition of the present invention at a predetermined concentration in an amount that can be used in a relatively short period of time.

(1) A two-component kit for preparing the disinfectant composition of the present invention by mixing a first liquid agent consisting of a weakly acidic aqueous solution of hypochlorous acid that does not contain the component (B) and a second liquid agent consisting of an aqueous solution of the component (B), the kit comprising:
The two-component kit is characterized in that, when the ratio of the mass of the second liquid to the mass of the first liquid to be mixed at the predetermined ratio is (mass of second liquid/mass of first liquid) ratio: X, X is 0.01 to 10, preferably 0.02 to 10, and more preferably 0.5 to 8, the effective chlorine concentration in the weakly acidic hypochlorous acid aqueous solution of the first liquid is equivalent to the effective chlorine concentration of the disinfectant composition to be prepared multiplied by (1+X), and the concentration of the component (B) in the aqueous solution of the second liquid is equivalent to the concentration of the component (B) in the disinfectant composition to be prepared multiplied by {(1+X)/X}.

(2) A two-component kit for preparing the disinfectant composition of the present invention, which comprises a first liquid agent consisting of a weakly acidic aqueous solution of hypochlorous acid that does not contain the component (B) and a second liquid agent consisting of an aqueous solution of the component (B), and which is prepared by mixing the first liquid agent, the second liquid agent, and water supplied from an external source in a predetermined ratio;
the ratio of the mass of the second liquid to the mass of the first liquid to be mixed in the predetermined ratio is (mass of second liquid/mass of first liquid) Y, and the ratio of the mass of the water to the mass of the first liquid to be mixed in the predetermined ratio is (mass of water/mass of first liquid) Z, respectively; Y is 0.01 to 2, preferably 0.02 to 2, more preferably 0.5 to 1.5, and Z is 2 to 50, preferably 2 to 40, more preferably 2 to 35; the effective chlorine concentration in the weakly acidic hypochlorous acid aqueous solution of the first liquid is equivalent to the effective chlorine concentration obtained by multiplying the effective chlorine concentration of the disinfectant composition, which is the target of preparation, by (1+Y+Z); and the concentration of the component (B) in the aqueous solution of the second liquid is equivalent to the concentration obtained by multiplying the concentration of the component (B) in the disinfectant composition, which is the target of preparation, by {(1+Y+Z)/Y}.

"Equivalent concentration" here means that the concentration is the same as the calculated concentration or is within ±20%, preferably ±10%, of that calculated concentration. Furthermore, the effective chlorine concentration in the disinfectant composition to be prepared is preferably 30 to 1000 ppm, particularly 50 to 500 ppm, and the concentration of component (B) is preferably 50 ppm by mass to 1.5% by mass, particularly 100 to 1500 ppm by mass. Furthermore, it goes without saying that neither of the liquid formulations in kits (1) and (2) above substantially contains (C) organic acids and their salts, or (D) ionic surfactants.

The disinfectant composition of the present invention contains molecular hypochlorous acid as its active ingredient, and is not alkaline or strongly acidic, which require careful handling. As a result, it has a high disinfecting effect, is relatively safe, and is easy to handle. For this reason, it is useful for disinfecting in a wide range of fields, including hospitals, food processing plants, educational facilities, and nursing homes.

Furthermore, the disinfectant composition of the present invention has the excellent advantage not found in conventional weakly acidic hypochlorous acid aqueous solution-based disinfectant compositions: it does not corrode metals (causing rust on metals) or leave deposits after rinsing with water. Therefore, it can be used on articles made of plastic, rubber, tile, brick, cement, glass, wood, cloth, nonwoven fabric, vinyl, leather, ceramics, etc., as well as articles containing metal, particularly articles containing steel, cobalt chromium, silver, zinc, brass, etc., which are prone to rust.

The germicidal cleaner of the present invention is characterized by containing the germicidal composition of the present invention. Here, the germicidal cleaner refers to a cleaner for removing dirt adhering to an object, and/or a germicidal cleaner for killing or removing (sterilizing or disinfecting) microorganisms such as bacteria adhering to an object. The germicidal cleaner of the present invention can be suitably used as a germicidal cleaner for cleaning and/or sterilizing objects at least a portion of whose surface is made of metal, particularly steel, cobalt chromium, silver, zinc, brass, or the like, which are prone to rust.

The germicidal cleaner of the present invention may consist solely of the germicidal composition of the present invention, but may also contain various additives, etc., as long as the additives and formulation do not impair the aforementioned effects. For example, a thickener can be added to improve adhesion to the object to be sterilized and to create a gel or paste. It is preferable to use inorganic particles as the thickener, and it is preferable to use inorganic particles with an average primary particle diameter of 5 nm to 100 nm.

The method of use of the bactericidal composition and the bactericidal cleaner of the present invention is not particularly limited. For example, the bactericidal composition may be brought into contact with an object by spraying, applying, immersing, or the like. Specific examples include spraying the area to be sterilized using a sprayer such as a trigger and then wiping it off; immersing the object to be sterilized in the bactericidal composition and then rinsing with water; misting the bactericidal composition with an ultrasonic sprayer and spraying it into a space; rubbing the object with the bactericidal composition by soaking it in an absorbent material such as cloth or nonwoven fabric; and applying the bactericidal composition to the object to be sterilized using a brush or syringe and then rinsing or wiping with water. Furthermore, when immersing the object to be sterilized in the bactericidal composition, ultrasound can be used to enhance the cleaning effect. Furthermore, the bactericidal composition may be used as a cleaning solution when using a wash dispenser used to clean and sterilize medical instruments.

The following examples and comparative examples will be used to explain the present invention in more detail, but the present invention is not limited to these in any way.

First, we will explain the nonionic surfactants and raw materials used in the production of weakly acidic hypochlorous acid water used in the examples and comparative examples; the method for preparing weakly acidic hypochlorous acid water; and the method for evaluating weakly acidic hypochlorous acid water.

(1) Raw materials, etc. [Nonionic surfactants containing no multiple bonds]
Polyglyceryl-10 laurate (manufactured by Daicel Corporation, hereinafter abbreviated as "PGLE")
Polyglyceryl-4 lauryl ether (manufactured by Daicel Corporation, hereinafter abbreviated as "PGLAL")
Polyoxyethylene (5) lauryl ether (manufactured by Nikko Chemicals Co., Ltd.; hereinafter abbreviated as "POELE")
Perfluoroalkyl group-containing nonionic surfactant: product name Surflon S-242 (manufactured by AGC Seimi Chemical Co., Ltd., hereinafter abbreviated as "S-242").

[Nonionic surfactants containing multiple bonds]
Polyoxyethylene (10) oleyl ether (manufactured by Nikko Chemicals Co., Ltd., hereinafter abbreviated as "POEOE").

[Anionic surfactants]
- α-olefin sulfonic acid sodium salt: product name K-Liboran PJ-400CJ (manufactured by Lion Specialty Chemicals Co., Ltd., hereinafter abbreviated as "PJ-400").

[Organic acid salt]
Trisodium citrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., hereinafter abbreviated as "STC")

[Raw materials used in the production of highly concentrated, weakly acidic hypochlorous acid water]
- NaClO aqueous solution with an effective chlorine concentration of 12.0% by mass (Neolux Super: supplied by Shimada Shoten)
Weakly acidic ion exchange resin Amberlite IRC-76 (H ⁺ type, manufactured by Organo Corporation, hereinafter abbreviated as "IRC76").

(2) Method for preparing weakly acidic hypochlorous acid water The 12.0% by mass NaClO aqueous solution was diluted with ion-exchanged water to adjust the effective chlorine concentration to 11,000 ppm, to prepare 2,400 ml of raw aqueous solution. Next, 200 ml of weakly acidic ion exchange resin IRC76 was measured, and the entire amount of the raw aqueous solution was added. The mixture was stirred for 20 minutes using a fluororesin stirring blade to uniformly disperse the weakly acidic ion exchange resin. During stirring, the pH of the mixture was monitored, and stirring was stopped when the pH decreased to 6.3. After stirring, the mixture was left to stand until the resin settled, and the supernatant hypochlorous acid aqueous solution was decanted and collected in a polyethylene container through a #200 filter cloth to prevent the resin from entering. The liquid was left at room temperature for 3 hours until the pH reached 4.8. The effective chlorine concentration after standing was 9,000 ppm.

(3) Evaluation method (3-1) Measurement of available chlorine concentration (production)
A portion of the sodium hypochlorite aqueous solution and the weakly acidic hypochlorous acid water was used as a sample solution, and the sample solution was diluted with ion-exchanged water at the following dilution ratio according to the effective chlorine concentration of the raw material solution to prepare a measurement sample, and the effective chlorine concentration after dilution was measured using an effective chlorine concentration measurement kit AQ-202 (Shibata Scientific Co., Ltd.). The effective chlorine concentration of the sample solution was calculated from the measurement result and the dilution ratio.
・Available chlorine concentration of raw solution 300 ppm or less: Do not dilute ・Available chlorine concentration of raw solution 301 to 900 ppm: Dilution ratio 3 times ・Available chlorine concentration of raw solution 901 to 3000 ppm: Dilution ratio 10 times ・Available chlorine concentration of raw solution 3001 to 15000 ppm: Dilution ratio 50 times

(3-2) pH Measurement The pH of the weakly acidic hypochlorous acid water and the disinfectant composition was measured using a pH meter F-55 (Horiba, Ltd.).

(3-3) Measurement of total metal ion concentration (ppm by mass) and calculation of C _E /C _A value Measurement samples were prepared by diluting the weakly acidic hypochlorous acid water and the disinfectant composition with ion-exchanged water to an effective chlorine concentration of 20 ppm. Measurement was performed using an ICP emission spectrometer iCAP6500DUO (Thermo Fisher Scientific), and the C _E /C _A value was calculated using the following formula (5).
C _E /C _A = measured value (ppm)/20 (5)

(3-4) Evaluation of Rust 40 ml of the sample solution was placed in a 50 cc glass bottle, and a dental steel bur ("Elasteel Bur (manufactured by Shofu Co., Ltd.)") was immersed in the solution. After a predetermined time, the presence or absence of rust was visually confirmed.
○: No rust was observed.
△: A little rust was observed.
×: Rust was clearly observed.

(3-5) Evaluation of storage stability 40 ml of sample solution was placed in a 50 cc glass bottle and stored at room temperature (10 to 23°C) for a predetermined time, after which the available chlorine concentration and pH were measured and changes from the initial values were confirmed. The available chlorine concentration during the storage stability evaluation was measured using a water quality test paper (Nissan Aqua Check HC).

(3-6) Cleaning Evaluation 40 ml of sample solution was placed in a 50 cc glass bottle, and a cleaning evaluation indicator TOSI (manufactured by PEREG GmbH) was immersed and left for 5 minutes. The indicator was removed, the plastic part of the indicator was broken, the measurement part was removed, and then lightly washed with water. Residual protein detection solution (manufactured by Saraya Co., Ltd.) was applied and left for 30 seconds. After lightly rinsing with water, the degree of cleaning was evaluated visually.

(3-7) Bacterial Disinfection Evaluation Tokuyama A-1α (manufactured by Tokuyama Dental Co., Ltd.) was used to prepare an alginate plate measuring 19 mm in length, 57 mm in width, and 3 mm in thickness. 100 μl of saliva was applied to one side of the alginate plate, which was then lightly rinsed with water and immersed in 200 ml of sample solution. After immersion for 30 seconds, the alginate plate was removed, and the saliva-treated surface of the alginate plate was lightly pressed against brain heart infusion medium, bringing the saliva-treated surface into contact with the entire medium. The alginate plate was removed, and after culturing in an incubator at 37°C for 1 week, the presence or absence of bacteria (colonies) was visually confirmed.

Example 1
18.7 ml of ion-exchanged water was added to 1.3 ml of the weakly acidic hypochlorous acid water with an effective chlorine concentration of 9000 ppm prepared in (2) above, and stirred with a stirrer for 1 minute. 0.4 g of surfactant PGLE and 19.6 g of ion-exchanged water were weighed into a separate container and stirred with a stirrer for 10 minutes until uniform. Just before each evaluation, 20 g of each prepared aqueous solution was placed in a 50 ml screw tube bottle and mixed by hand for 10 seconds to obtain a disinfectant composition. The total metal ion concentration (ppm by mass) of the obtained disinfectant composition was measured, and the _CE / _CA value was calculated. The disinfectant composition and the _CE / _CA value are shown in Table 1.
Separately, a disinfectant composition prepared in the same manner was used to evaluate rust on a dental steel bur and its storage stability. The evaluation results are shown in Tables 2 and 3.

Examples 2 to 5, Comparative Examples 1 to 3
A fungicide composition was prepared in the same manner as in Example 1, except that the type of surfactant used was changed as shown in Table 1, and rust and storage stability were evaluated. The evaluation results are shown in Tables 2 and 3.

Examples 6 to 13, Comparative Examples 4 to 7
The amount of ion-exchanged water used to dilute Dentzia and the amount of surfactant were changed, and disinfectant compositions were prepared in the same manner as in Example 1, and rust evaluation was performed. In addition, cleaning and disinfection evaluations were performed in Examples 6, 7, 8, and 11.

The evaluation results are shown in Tables 4 and 5.

In the case of the weakly acidic hypochlorous acid water with an effective chlorine concentration of 300 ppm (Comparative Example 1), obvious rust was observed after 5 minutes, but in the disinfectant compositions with an effective chlorine concentration of 300 ppm, no rust was observed even after 1 day in Examples 1 to 3. Only slight rust was observed after 24 hours in Example 4 and 3 hours in Example 5. Furthermore, in Examples 1 to 4, no change in effective chlorine concentration or pH was observed after 1 day of storage at room temperature. However, in Example 5, which used a surfactant containing a carbon-carbon multiple bond in the molecule, the effective chlorine concentration began to gradually decrease immediately after production but remained at 50 ppm for up to 30 minutes.

Similarly, in Examples 6 to 13 and Comparative Examples 4 to 6, the rust prevention effect was confirmed by adding a surfactant regardless of the available chlorine concentration or surfactant concentration.

In Examples 6, 7, 8, and 11, it was confirmed that the cleaning effect was higher than that of cleaning with sterilized water in Comparative Example 7. Furthermore, in the sterilization evaluation, no colonies were formed in Examples 6, 7, 8, and 11, confirming the sterilization effect.

The above results confirmed the rust-preventing effect of the surfactant, and also showed that the absence of easily oxidizable compounds such as organic acids improves storage stability.

Claims (5)

A germicidal cleaner for cleaning and/or sterilizing an article having at least a portion of its surface formed of metal, comprising:
A weakly acidic aqueous hypochlorous acid solution having a pH of 3.0 or more and 7.0 or less, in which (A) molecular hypochlorous acid and (B) at least one nonionic surfactant selected from the group consisting of polyglycerol fatty acid esters and fluorine-based nonionic surfactants are dissolved,
The bactericidal cleaning agent is characterized by containing a bactericidal composition consisting of a weakly acidic hypochlorous acid aqueous solution, in which the contents of (C) an organic acid and its salt, and (D) an ionic surfactant are each 10 mass ppm or less, based on the total mass of the weakly acidic hypochlorous acid aqueous solution. The effective chlorine concentration (ppm by mass) contained in the weakly acidic hypochlorous acid aqueous solution is represented by C _A ;
The total concentration (ppm by mass) of the nonionic surfactant (B) contained in the weakly acidic aqueous hypochlorous acid solution is represented by C _B ,
The total concentration (ppm by mass) of the (C) organic acid and its salt that may be contained in the weakly acidic hypochlorous acid aqueous solution is represented by C _/C ;
When the total concentration (ppm by mass) of the ionic surfactant (D) that can be contained in the weakly acidic aqueous hypochlorous acid solution is represented by C _D ,
The following formulas (1) to (3)
0.5≦C _B /C _A ≦1000 (1)
C _C /C _A <0.05 (2)
C _D /C _A <0.05 (3)
The bactericidal cleaning agent according to claim 1 , which satisfies all of the conditions shown above. The bactericidal cleaner according to claim 2 , wherein _CE / _CA is 0.35 or less when the total concentration (quantity ppm) of metal ions that can be contained in the weakly acidic hypochlorous acid aqueous solution is represented by _CE . A two-component kit for preparing the disinfectant composition of claim 1, comprising a first liquid agent consisting of a weakly acidic aqueous solution of hypochlorous acid that does not contain the component (B) and a second liquid agent consisting of an aqueous solution of the component (B) , wherein the first liquid agent and the second liquid agent are mixed in a predetermined ratio,
When the ratio of the mass of the second liquid to the mass of the first liquid mixed at the predetermined ratio is (mass of second liquid/mass of first liquid) ratio: X, X is 0.01 or more and 10 or less,
The effective chlorine concentration in the weakly acidic hypochlorous acid aqueous solution of the first liquid agent is equal to the effective chlorine concentration of the disinfectant composition to be prepared multiplied by (1 + X),
The concentration of the (B) component in the aqueous solution of the second liquid is equivalent to the concentration of the (B) component in the disinfectant composition to be prepared multiplied by {(1 + X) / X};
The two-component kit is characterized in that A two-component kit for preparing the disinfectant composition of claim 1, comprising a first liquid agent consisting of a weakly acidic aqueous solution of hypochlorous acid that does not contain the component (B) and a second liquid agent consisting of an aqueous solution of the component (B), the kit being for preparing the disinfectant composition of claim 1 by mixing the first liquid agent, the second liquid agent, and water supplied from an external source in a predetermined ratio,
When the mass ratios of the second liquid and the water to the mass of the first liquid mixed at the predetermined ratio are (mass of second liquid/mass of first liquid): Y and (mass of water/mass of first liquid): Z, respectively, Y is 0.01 or more and 2 or less, and Z is 2 or more and 50 or less,
The effective chlorine concentration in the weakly acidic hypochlorous acid aqueous solution of the first liquid agent is equal to the effective chlorine concentration of the disinfectant composition to be prepared multiplied by (1 + Y + Z),
The concentration of the (B) component in the aqueous solution of the second liquid is equivalent to the concentration of the (B) component in the disinfectant composition to be prepared multiplied by {(1 + Y + Z) / Y}.
The two-component kit is characterized in that