JPH09151104A - Bactericidal water having persistent antibacterial activity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare bactericidal water having wide application range such as the sterilization for agriculture and horticulture, sterilization of tableware and food and sterilization of sandbox, free from residual activity, exhibiting high sterilization action and having excellent persistence of the bactericidal effect. SOLUTION: This bactericidal water can be produced by mixing an anodic water prepared by membrane electrolysis of an electrolyte aqueous solution with a liquid selected from an aqueous solution of chitosan, wood vinegar containing chitosan and chitosan-containing amino acid liquid. The anodic water is e.g. discharged from an anodic chamber in a membrane electrolysis of an electrolyte solution containing e.g. NaCl at a concentration of preferably about 0.01-5.0wt.%. The aqueous solution of chitin is prepared by using (1,4)-2-amino-2- deoxy-β-D-glucose which is a polysaccharide having glucosamine unit bonded in a β-1,4 form and produced by the deacetylation of chitin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to sterilization for agriculture and horticulture,
It is used in a wide range of fields including sterilization of tableware and food, sterilization in sandboxes, etc., and relates to sterilizing water that can replace conventional sterilizing agents. The present invention also relates to sterilized water having excellent antibacterial durability.

[0002]

2. Description of the Related Art Conventionally, an aqueous solution of hypochlorous acid, sodium hypochlorite or the like has been known as sterilizing water for sterilizing tableware and foods, and is used in such an aqueous solution to enhance its sterilizing effect. On the site, those with hydrochloric acid added have been used.

Disclosed in Japanese Patent Publication No. 7-8768, for example, is a sterilizing water that can be used safely and at low cost for food environmental hygiene, food materials, etc. by solving the problem of food hygiene caused by the addition of hydrochloric acid and the like. As described above, it has been conventionally known that water or acidic anodic water electrolyzed by adding salt, potassium chloride or the like to water can be used. In such electrolysis, since hypochlorous acid is generated in acidic anode water, the sterilizing action is used to use the anode water as sterilizing water.

On the other hand, chitosan, which is a deacetylated product of chitin that forms a biological skeleton in coexistence with proteins and calcium carbonate and is a polysaccharide in which glucosamine is bound to β-1,4 type, is spore germination and growth of phytopathogenic fungi. It is known to have a protective function against pathogen infection (“Textile and Industry”, Textile Society of Japan, Vol. 42, No. 6, 1986).

Although chitosan itself has a weak bactericidal action, it has a long-lasting antibacterial action. Therefore, as shown in, for example, JP-A-53-59027, chitosan contains chitosan as an agricultural and horticultural antiviral agent. Is used.

[0006]

The conventional sterilizing water or sterilizing agent, by its nature, has a so-called residual toxicity in which a toxic substance remains when used in a large amount.

On the other hand, the above-mentioned electrolyzed anodic water has a strong bactericidal action and has no persistence, but the bactericidal action due to hypochlorous acid is not long-lasting because of its decomposition rate.

On the other hand, although chitosan has an antibacterial action as described above, it has a weak bactericidal action. Further, it is known that a chitosan solution and a wood vinegar solution having a weak bactericidal action are mixed and used (Japanese Patent Laid-Open No. 6-287104), but it is still not sufficient in terms of antibacterial durability.

It is an important issue for sanitary control of sterilized water that sterilization is carried out to reduce the number of bacteria, to suppress the growth of bacteria to provide antibacterial durability and to have no persistence. Similar properties are required for bactericides such as pesticides, but generally, sterilization and residual toxicity are correlated with each other, and if the bactericidal action is strong, the residual toxicity becomes strong.
Conventionally, there has been a demand for sterilizing water that does not have such a residual property, has a large bactericidal action, and has antibacterial and persistent properties, but such sterilizing water has not been known so far.

Therefore, an object of the present invention is to provide a novel sterilizing water which has no persistence, has a large bactericidal action, and has excellent antibacterial durability.

[0011]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have found that anodic water by electrolysis and chitosan aqueous solution, which had been used only individually until now, When using a combination of chitosan-containing wood vinegar solution and chitosan-containing amino acid solution,
The inventors have found that the above problems can be solved and completed the present invention.

That is, the sterilizing water of the present invention is characterized by mixing anodic water obtained by diaphragm electrolysis of an aqueous electrolyte solution with an aqueous chitosan solution.

The sterilizing water of the present invention is characterized by mixing anodic water obtained by diaphragm electrolysis of an aqueous electrolyte solution and chitosan-containing wood vinegar solution.

Further, the sterilizing water of the present invention is characterized by mixing anodic water obtained by diaphragm electrolysis of an aqueous electrolyte solution and a chitosan-containing amino acid solution.

Here, the chitosan-containing wood vinegar solution is an aqueous solution obtained by mixing a chitosan aqueous solution and a wood vinegar solution, and the chitosan-containing amino acid solution is obtained by mixing a chitosan aqueous solution and an amino acid aqueous solution. It is an aqueous solution.

In the present invention, it is important to mix chitosan in the form of an aqueous solution with the anode water obtained by the diaphragm electrolysis of an aqueous electrolyte solution. In the state where the powdered chitosan is directly dispersed in the anode water. When mixed, the two do not form a homogeneous phase, and the object of the present invention cannot be achieved.

Further, in the sterilized water of the present invention, when anodic water obtained by diaphragm electrolysis of an electrolyte aqueous solution and chitosan aqueous solution are mixed with wood vinegar solution or amino acid aqueous solution and used, excellent bactericidal and antibacterial properties are obtained. Chitosan,
The effects peculiar to wood vinegar and amino acids are obtained without being hindered, and the usefulness of the sterilizing water of the present invention is remarkably enhanced.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the anode water obtained by the diaphragm electrolysis of an aqueous electrolyte solution is chloride such as sodium chloride, potassium chloride or calcium chloride, preferably 0.01 to 5.0% by weight. It refers to acidic electrolyzed water discharged from the anode chamber in the diaphragm electrolysis of an electrolytic aqueous solution containing a certain concentration. Such electrolyzed water has a bactericidal action, and the action is that active oxygen (hydroxy radical) generated by electrolysis of water and chlorine ions present in water, hypochlorous acid, and PH value and redox potential of microorganisms. This is due to exceeding the survival range.

For example, when sodium chloride is used as the electrolyte, chlorine, hypochlorous acid,
Residual chlorine such as hypochlorite ion and other chlorine compounds is 10 ppm or more, preferably 20 ppm or more, and the pH value is 2.0 to 6.5, preferably 2.0.
The conditions of electrolysis are set so as to be in the range of to 6.0. Further, a porous membrane can be used as the membrane in the diaphragm electrolysis in the present invention, but an ion exchange membrane is preferably used. In addition, electrolysis can be performed according to a conventional method and does not require any particular conditions.

The bactericidal action of the anodic water of the diaphragm electrolysis obtained as described above is not sustainable because the components are unstable, and thus has no residual toxicity.

Next, the chitosan aqueous solution mixed with the anodic water for the diaphragm electrolysis will be described. The chitosan used therein is the deacetylated product of chitin as described above, in which glucosamine is bound to β-1,4 type. Polysaccharide (1,
4) -2-amino-2-deoxy-β-D-glucose. This is a polymer having an amino group that closely resembles the molecular structure of cellulose and has the property of being difficult to decompose. Its structural formula is

[0022] The structure itself is known.

Chitosan is poorly soluble in water as it is, and is hardly dissolved even if it is added to the anode water as it is.
On the other hand, since chitosan has a free amino group in its molecule, it forms a salt with acetic acid, an organic acid such as lactic acid, formic acid, and propionic acid, and an inorganic acid such as hydrochloric acid and nitric acid to dissolve. Therefore, in the present invention, chitosan is dissolved in water in the form of such salt to obtain an aqueous chitosan solution. That is, although chitosan is theoretically dissolved with a stoichiometric amount of acid, it is generally dissolved with an acid excess ratio of 20 to 200%. The chitosan used in the present invention preferably has a low molecular weight from the viewpoint of the problem of solubility of chitosan and obtaining a high chitosan concentration, and the low molecular weight is easily possible by a conventionally known method, The average molecular weight calculated from the viscosity formula is 31,000.
Those in the range of to 12,000 are preferable. The chitosan concentration in the chitosan aqueous solution is 0.5 to 10% by weight, preferably 1 to 6% by weight.

The thus-obtained aqueous chitosan solution is then mixed with the above anodic water for diaphragm electrolysis. In the sterilized water of the present invention, the mixing ratio (weight ratio) of the chitosan aqueous solution to the anode water can be appropriately changed according to its specific application, and it is not particularly limited, but both are mixed. The concentration of chitosan in the sterilized water obtained as a result is 0.00
0125-0.05% by weight, preferably 0.00025
~ 0.03% by weight.

Further, in the present invention, a chitosan-containing solution of wood vinegar can be easily obtained by mixing wood vinegar with an aqueous solution of chitosan, and peculiar effects such as bactericidal property and growth promoting property of wood vinegar are imparted. It In such a case, the wood vinegar solution is preliminarily subjected to gelation-preventing treatment so as not to gel even when mixed with the chitosan solution. The stable chitosan-containing wood vinegar solution thus prepared is mixed with anode water.
The mixing ratio (weight ratio) of the chitosan aqueous solution to the wood vinegar and the mixing ratio of the anode water to the chitosan-containing wood vinegar solution can be changed to some extent according to the specific application, but the mixing ratio of the chitosan aqueous solution to the wood vinegar (weight Ratio) is
The mixing ratio (weight ratio) of the anode water to the chitosan-containing wood vinegar is 0.05: 100 to 1: 100.
It is. The concentration of chitosan in the sterilized water thus obtained is 0.000125-0.05% by weight, preferably 0.00025-0.03% by weight. The wood vinegar is a low-purity acetic acid obtained by decomposing and distilling wood tar or pine tar, and has a weak bactericidal action itself.

Further, in the present invention, a chitosan-containing amino acid solution can be easily obtained by mixing an aqueous solution of amino acid with an aqueous solution of chitosan, and specific effects such as the promotion of growth of amino acid and the sugar content Up can be imparted. In order to obtain the amino acid aqueous solution, for example, there is a method such as anaerobic fermentation of the processed residue of fish. Aspartic acid, serine, glutamic acid, glycine, alanine,
Valine, leucine, lysine, arginine, proline and the like are included. The mixing ratio (weight ratio) of the chitosan aqueous solution to the amino acid aqueous solution and the mixing ratio (weight ratio) of the anodic water to the chitosan-containing amino acid solution are the same as in the case of the wood vinegar solution.

As described above, the sterilizing water of the present invention containing the anode water and chitosan has a large bactericidal action without residual due to the synergistic effect of the bactericidal action of the anode water and the antibacterial action of chitosan.
Moreover, it has the characteristic of exhibiting antibacterial durability.

The amino group of chitosan is positively charged and electrically attracts the negative charge of microorganisms. Chitosan attracted to the microorganisms is taken into the cells of the microorganisms to inhibit the growth and exhibit an antibacterial action. Chitosan remains a residue because it is a substance that is difficult to decompose, but since it is not toxic, it retains its antibacterial effect without residual toxicity.

Various additives can be added to the sterilizing water of the present invention. For example, by adding an agricultural chemical as an auxiliary agent, it is possible to reduce the amount of agricultural chemicals.

[0030]

Next, the present invention will be described in detail with reference to examples. Anode water used in this example, a chitosan aqueous solution,
A method for preparing a chitosan-containing wood vinegar solution and a chitosan-containing amino acid solution will be described. [Preparation of Anode Water] Using a known electrolyzer equipped with a cation exchange membrane as a diaphragm, a salt solution having a concentration of 0.07% by weight was supplied to the anode chamber for electrolysis. The obtained electrolyzed water immediately after electrolysis was discharged from the anode chamber, and the electrolyzed water (acidic electrolyzed water:
PH 2.7, available chlorine 30 ppm).

[Preparation of Chitosan Aqueous Solution] Chitosan whose molecular weight has been previously hydrolyzed by heating with hydrochloric acid is neutralized with caustic soda to be precipitated, and then dissolved with acetic acid to obtain a chitosan concentration of 3
A wt% and 6 wt% chitosan aqueous solution was obtained.

[Preparation of Chitosan-Containing Wood Vinegar Solution] The chitosan aqueous solution having a chitosan concentration of 6% by weight and the gelation-preventing acetic acid concentration of 4.4% by weight wood vinegar solution were mixed at a weight ratio of 1: 1. Then, a chitosan-containing wood vinegar solution having a chitosan concentration of 3% by weight was obtained.

[Preparation of chitosan-containing amino acid solution] The processed residue of fish was anaerobically fermented to obtain an amino acid aqueous solution having a nitrogen content of 2.2%. Similar to the preparation of the chitosan-containing wood vinegar solution, the amino acid aqueous solution and the chitosan aqueous solution having a chitosan concentration of 6% by weight were mixed at a weight ratio of 1: 1 to obtain a chitosan-containing amino acid solution having a chitosan concentration of 3% by weight. .

Example 1 The chitosan aqueous solution having a chitosan concentration of 3% by weight and the anode water were mixed at a weight ratio of 0.5: 100 to prepare an aqueous solution having a chitosan concentration of 0.015% by weight. Used as sterile water.

Example 2 The chitosan-containing wood vinegar solution having a chitosan concentration of 3% by weight and the anode water were mixed at a weight ratio of 0.5: 100 to prepare an aqueous solution having a chitosan concentration of 0.015% by weight. This was used as sterile water.

Example 3 A chitosan-containing amino acid solution having a chitosan concentration of 3% by weight and the anode water were mixed in a weight ratio of 0.5: 100 to prepare an aqueous solution having a chitosan concentration of 0.015% by weight.
This was used as sterile water.

Comparative Example 1 The chitosan aqueous solution having a chitosan concentration of 3% by weight and purified water were mixed at a weight ratio of 0.5: 100 to prepare an aqueous solution having a chitosan concentration of 0.015% by weight, which was sterilized. Used as water.

Comparative Example 2 A chitosan-containing wood vinegar solution having a chitosan concentration of 3% by weight and purified water were mixed at a weight ratio of 0.5: 100 to prepare an aqueous solution having a chitosan concentration of 0.015% by weight. Was used as sterile water.

Comparative Example 3 A chitosan-containing amino acid solution having a chitosan concentration of 3% by weight and purified water were mixed at a weight ratio of 0.5: 100 to prepare an aqueous solution having a chitosan concentration of 0.015% by weight. Was used as sterile water.

Comparative Example 4 The anode water was directly used as sterilizing water.

The sterilized waters of Examples 1 to 3 and Comparative Examples 1 to 4 were sprayed on the sandboxes in the parks, and changes in the number of E. coli cells over time were investigated. Such survey is 10 cm in summer
The number of coliforms per 100 g was calculated by using sand having a depth of. As a reference example, changes over time in the number of E. coli cells were also investigated in the case of no treatment without using any sterilized water. The results obtained are shown in Table 1 below.

[0042]

[Table 1]

[0043]

As described above, the sterilizing water of the present invention has the effect that it has no residue and exhibits a safe sterilizing action, and exhibits excellent antibacterial durability. Therefore, excellent effects are exhibited as a sandbox in a park, for agriculture, and as a fungicide.

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Claims (3)

[Claims] 1. A sterilizing water having antibacterial durability, which is obtained by mixing anode water obtained by diaphragm electrolysis of an aqueous electrolyte solution with an aqueous chitosan solution. 2. A sterilizing water having antibacterial durability, which is characterized by mixing anodic water obtained by diaphragm electrolysis of an aqueous electrolyte solution and chitosan-containing wood vinegar solution. 3. A sterilizing water having antibacterial durability, characterized by mixing anodic water obtained by diaphragm electrolysis of an aqueous electrolyte solution and a chitosan-containing amino acid solution.