JPH0940502A - Antibacterial agent composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antibacterial agent having low solution viscosity, easily formable in the form of film, sheet, etc., and giving a water-insoluble product resistant to discoloration simply by drying. SOLUTION: This antibacterial agent composition is produced by dissolving chitosan in a solution of malonic acid, L-malic acid or their mixture and adding an antibacterial metallic ion to the obtained chitosan solution.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an antibacterial agent composition, which uses chitosan as a base material and can be in a solution form or a solid form. Therefore, foods, cosmetics, pharmaceuticals, papers, fibers, films, sheets, The present invention also relates to an antibacterial agent composition that can be effectively used for antibacterial and antifungal purposes.

[0002]

2. Description of the Related Art Since chitosan has an antibacterial property by itself, it is used as it is as a solution or powder in fibers, cosmetics and the like. However, since the antibacterial property is weak, a large amount must be used in order to provide the product with sufficient antibacterial activity. On the other hand, an antibacterial agent using an antibacterial metal has a strong antibacterial property and an effect can be obtained by using a small amount, but the carrier is often a ceramic and cannot be used as a solution. Japanese Patent Application No. 54-31598 discloses a bactericidal sheet material of chitosan, which is prepared by adhering a strong coating film of free chitosan to the inside and outside of the sheet material, and then applying this to copper sulfate or silver nitrate. It is impregnated with a dilute solution, and copper ions or silver ions are chelated to the free chitosan attached to the sheet material, and then dried to obtain a bactericidal sheet material. In this method, the antibacterial effect of silver is limited to the surface of chitosan, and the persistence of antibacterial activity is very short.In addition, the chelate bond of silver ion with chitosan by silver nitrate is weak, and the discoloration of the sheet due to the precipitation of silver is remarkable. Therefore, there is a problem that the commercial value of the sheet is reduced, and its use is limited. On the other hand, the present inventors disclose an antibacterial agent composition in which an antibacterial metal ion is contained in chitosan in “Antibacterial Agent Composition” Japanese Patent Application No. 7-99485, but the viscosity of dissolved chitosan is high and a film is formed. However, there are problems that it is difficult to manufacture sheets and the like, and that discoloration occurs.

[0003]

As described above, when chitosan is used as a base material, it becomes a solution or a film and can be applied to a wide range of applications. However, when it is desired to utilize its antibacterial property. Must be used in a large amount due to its weak antibacterial property, which may affect the quality originally required for its application, and even if no quality problem occurs, chitosan is expensive. not afford to be used for any such products for certain. On the other hand, liquid antibacterial agents using silver cause precipitation of metallic silver during standing, discoloration is severe, and it dissolves in water even after drying, so devise a binder so that it does not dissolve in water, perform high heat treatment, etc. Processing is required. The present invention provides an antibacterial agent composition that can be used as a solution by taking advantage of the excellent characteristics of chitosan as a base material.

[0004]

DISCLOSURE OF THE INVENTION As a result of studying the above-mentioned problems, the present inventors have found that chitosan is replaced with malonic acid or L
-Dissolved in a solution of malic acid, or a mixed solution of these, and by containing a metal ion having an antibacterial action, antibacterial property can be obtained with a small amount of use, it does not dissolve in water only by drying, and discoloration is suppressed. It was found that the purpose of was achieved. Examples of the metal ion having antibacterial properties include silver,
There are copper, zinc, gold, platinum, tin, lead, nickel and the like. This composition can be a solution type antibacterial agent by adding a water-soluble metal salt of an antibacterial metal to a chitosan solution dissolved in a solution of malonic acid or L-malic acid or a mixed solution thereof and stirring the mixture. . The antibacterial water-soluble metal salt can be selected from general industrial chemicals and complex compounds. Examples of silver ions include silver nitrate, silver sulfate, silver acetate, silver lactate, silver perchlorate, ammine silver sulfate, and diammine silver nitrate.
Silver lactate and silver acetate are preferred. The copper ions include copper nitrate, copper sulfate, copper acetate, copper formate, and copper perchlorate, but copper nitrate and copper formate are preferable. As zinc ions, zinc nitrate, zinc sulfate, zinc acetate, zinc perchlorate,
Zinc thiocyanate and the like can be mentioned, and other metals can use the same water-soluble metal salts as these. The concentration of the dilute acid solution in which chitosan is dissolved may be 0.01 to 20%, preferably 10% or less as long as chitosan is dissolved. The concentration of the chitosan solution prepared by using this dilute acid solution varies depending on the method of using the antibacterial solution, but it is sufficient if the concentration of the antibacterial metal is 0.01% or more. %, Preferably 0.1% to 3%. The amount of antibacterial metal added is 0.
The maximum amount that can be contained in chitosan above 2ppm (based on chitosan solution) (100 based on chitosan)
%), Preferably 1 ppm or more for a chitosan solution and 50% for chitosan. The chitosan antibacterial agent prepared in this way causes almost no discoloration, so drainage and circulating water purification in a solution state, suppression of phytopathogenic fungi, and chitosan have good adhesion to fibers, paper, etc. As an antibacterial and deodorant coating agent for soybean fibers, it can be used in many methods such as powdering and kneading into a resin. In addition, if a highly safe metal such as silver, zinc, or copper is used as the antibacterial metal, it can be used in a very wide range such as foods, cosmetics and medicines. Hereinafter, the present invention will be described specifically with reference to examples.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION

[Example 1] 1 g of chitosan in 100 ml of 1% malonic acid solution
After dissolution, add 0.15 g of silver acetate and stir well.

[0006]

Example 2 After dissolving 0.3 g of chitosan in 100 ml of a 3% L-malic acid solution, 0.286 g of silver lactate was added and well stirred.

[0007]

Example 3 0.8 g of chitosan was added to 100 ml of a 0.5% L-malic acid solution, 0.3 g of silver acetate and 0.08 g of silver lactate were added, and the mixture was stirred well.

[0008]

EXAMPLE 4 100 ml of a 2% solution of malonic acid was added with chitosan.
After dissolving 5 g, add 0.763 g of silver lactate and stir well.

[0009]

Example 5 3 ml of chitosan was added to 100 ml of 5% malonic acid solution.
g after dissolution, 5.33 g of copper formate and 1.74 of zinc nitrate
Add g and stir well.

[0010]

Example 6 Antibacterial activity test 1 Examples 1 to 5 in a solution of E. coli at 6.1 × 10 ⁴ cells / ml.
1% of each solution was added, and after 24 hours, the number of bacteria in the solution was measured. As a result, the number of bacteria was 0. When the same test was conducted with a solution of 7.4 × 10 ⁴ Staphylococcus aureus / ml, the number of all bacteria was 0. For comparison, the numbers of bacteria of the Escherichia coli solution and Staphylococcus aureus solution after 24 hours were 7.3 × 10 ⁵ cells / ml in the Escherichia coli solution and 5.2 × 10 ⁵ cells / ml in the S. aureus solution. .

[0011]

Example 7 Discoloration test As a comparative example, 1 ml of a 1% citric acid solution was added to 1 ml of chitosan.
After dissolving g, 0.15 g of silver acetate is added and stirred well. Using Examples 1 to 5 and the above Comparative Example, a chitosan film was prepared on glass at room temperature, subjected to an outdoor UV exposure test, and subjected to a discoloration test. The results are shown in Table 1.

[0012]

[Table 1]

From these results, it is understood that the silver-containing antibacterial agent using chitosan dissolved in a solution of malonic acid or L-malic acid has very little discoloration.

[0014]

Industrial Applicability As described above, chitosan is dissolved in a solution of malonic acid or L-malic acid, or a mixed solution thereof, and a metal ion having an antibacterial action is added to the chitosan to form a film, sheet or the like. A conventional antibacterial agent for chitosan, which has the characteristics that a low viscosity solution type antibacterial agent that is easy to manufacture can be obtained, antibacterial activity can be obtained by using a small amount, it does not dissolve in water only by drying, and discoloration is suppressed. It provides properties not found in the composition.

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Claims (4)

[Claims] 1. An antibacterial agent composition containing a metal ion having an antibacterial action in a chitosan solution dissolved in a solution of malonic acid or L-malic acid, or a mixed solution thereof. 2. A metal ion having an antibacterial action is silver, copper,
The antibacterial agent composition according to claim 1, which comprises one or more metal ions selected from zinc, gold, platinum, tin and nickel. 3. The antibacterial composition according to claim 1, wherein silver lactate is used as the metal ion. 4. An antibacterial chitosan film, sheet and powder obtained by drying the antibacterial composition of claim 1.