JPH10114611A - Antimicrobial powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antimicrobial powder excellent in germicidal and propagation-suppressing effects on fungi and bacteria, and usable even in e.g. a kitchenware needing food safety without anxiety. SOLUTION: This antimicrobial powder comprises an antimicrobial agent 1 composed of 30-80wt.% silicon carbide or silicon dioxide 2, 10-40wt.% aluminum oxide 3 and 10-30wt.% titanium dioxide 4 after calcination, having a mean particle size of <=1μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is intended for use in hospital-related medicines, for example, after being incorporated into paints or synthetic resin materials for the purpose of sterilizing or suppressing the growth of fungi such as molds and yeasts, and bacteria such as pathogens and germs. The present invention relates to an antibacterial powder used for materials, home hygiene products, home electric appliances, etc., particularly kitchen products requiring food safety.

[0002]

2. Description of the Related Art Antibacterial powders of this type include organic and inorganic powders. As the former organic type, for example, elution type antibacterial agents such as thiazole type, imidazole type and thiazoline type are known. As the latter inorganic type, for example, a silver-containing zeolite type antibacterial agent is known.

[0003]

However, the above-mentioned organic eluting antibacterial agents exhibit an antibacterial effect at an early stage, but the durability of the antibacterial effect is short due to severe consumption due to elution of the drug over time. In addition, it has an antibacterial effect on mold, but has a problem that it has a weak antibacterial effect on bacteria. Further, for example, when an organic elution-type antibacterial agent is added to a paint for baking and used, there is a problem that if the baking and drying temperature of the coating is high, the active ingredient is thermally decomposed and the antibacterial effect is almost lost. In addition, since the elution-type antibacterial agent exerts an antibacterial action by elution of the drug, it has a problem in food safety, and its use in kitchenware is often regulated.

On the other hand, an inorganic silver-containing zeolite-based antibacterial agent has an effect only on bacteria in contact with the surface, and thus has no antibacterial effect when water or dust adheres to the surface.
Antibacterial activity is limited. In addition, zeolite containing silver is chemically created so that silver is held in the state of silver ions (Ag ⁺ ), so that the antibacterial effect of silver ions when the dust in the atmosphere adheres to the surface is charged. Fades. Furthermore, silver ions exert a bactericidal action by an oligodynamic action, but a passive oxide film of silver oxide is formed on the surface upon contact with water or air, so that the antibacterial effect is reduced. In addition, there is a problem in food safety due to elution of Ag ⁺ . When used in kitchenware use bleach chlorine etc. or Ag in the environment ⁺ and Cl ^- undergoes a chemical reaction, there would be no antimicrobial effect.

[0005] An object of the present invention is to improve the effect of disinfecting fungi and bacteria and suppressing the growth of the fungus by devising the composition of the inorganic antibacterial agent, and to reduce the necessity for kitchenware and the like that require food safety. An object of the present invention is to provide an antibacterial powder that can be used with care.

[0006]

That is, the antibacterial powder of the present invention has an average particle diameter of 1 μm as schematically shown in FIG.
m or less of the antibacterial agent 1, wherein the antibacterial agent 1 is composed of 30 to 80% by weight of silicon carbide or silicon oxide 2, 10 to 40% by weight of aluminum oxide 3, and 10 to 30% by weight of titanium oxide 4. It is characterized by being fired. The antibacterial agent is manufactured by baking at 700 to 900 ° C. to have an average particle size of 1 μm or less. By setting the average particle size to 1 μm or less, the surface area ratio becomes much larger than that of a conventionally used antibacterial agent having an average particle size of 10 μm or more, and highly efficient radiation of electromagnetic waves in the infrared region from the antibacterial agent component. Is possible. The average particle size of each composition of the antibacterial agent is 0.01 to
It is about 0.3 μm.

[0007]

The antibacterial powder of the present invention is blended with, for example, a paint or a synthetic resin material to enhance or improve the antibacterial properties of a coated steel plate or various synthetic resin molded articles manufactured using such a material. Provides antibacterial properties. Specifically, to radiate electromagnetic waves in the infrared region from the antimicrobial agent comprising the above composition, to resonate and excite water molecules of environmental water essential for water and its propagation in cells that form general bacteria, It can inhibit the physiological function of cells and suppress the growth of bacteria. At this time, the surface area ratio is increased by setting the average particle size of the antibacterial agent to 1 μm or less, so that the radiation efficiency of the electromagnetic wave in the infrared region is increased, and the bactericidal action on the bacterial cells and the effect of suppressing the proliferation are correspondingly increased. Will be enhanced.

[0008] Since the above-mentioned antibacterial agent is obtained by firing inorganic components, it does not deteriorate even if it is applied to a metal plate and baked at a high temperature. Further, since it does not elute the drug but exerts an antibacterial action by the emission of electromagnetic waves in the infrared region, there is no problem in terms of food safety. Therefore, it can be safely used for kitchen utensils and the like.

[0009] Silicon carbide or silicon oxide emits electromagnetic waves almost uniformly in the near infrared to far infrared region, and resonates and excites water molecules to suppress the growth of bacteria. Silicon carbide or silicon oxide is effective if the mixing ratio is 30 to 80% by weight.

[0010] Aluminum oxide can radiate electromagnetic waves in the far-infrared region, thereby suppressing the growth of bacteria. However, the effect of aluminum oxide is weak when it is less than 10% by weight, and the effect is saturated when it exceeds 40% by weight.

Titanium oxide is resonated and excited by external light energy, particularly electromagnetic waves in the ultraviolet region, creating a strong oxidizing power and reliably sterilizing general bacteria over a wide area. However, if it is less than 10% by weight, the bactericidal properties are remarkably reduced, and even if it exceeds 30% by weight, a remarkable bactericidal effect cannot be obtained.

[0012]

【Example】

[Examples 1 to 5] Chromate treatment of galvanized steel sheet,
Next, the following antibacterial agent (antibacterial powder) and a resin paint were applied to one surface of the galvanized steel sheet and baked and dried with the added amount of the antibacterial agent as shown in the table of FIG. The plate temperature at the time of baking was 215 ° C., and the dry film thickness was 15 μm. (1) Antibacterial agent (i) Antibacterial agent A A fired body having a composition of 50% by weight of silicon carbide, 30% by weight of aluminum oxide and 20% by weight of titanium oxide and having an average particle size of 0.9 μm was used. (ii) Antibacterial agent B A fired body having a composition of 70% by weight of silicon oxide, 15% by weight of aluminum oxide and 15% by weight of titanium oxide and having an average particle size of 0.6 μm was used. (iii) Antibacterial agent C A fired body having a composition of 30% by weight of silicon carbide, 40% by weight of aluminum oxide and 30% by weight of titanium oxide and having an average particle size of 0.7 μm was used. (iv) Antibacterial agent D A fired body having a composition of 80% by weight of silicon carbide, 10% by weight of aluminum oxide and 10% by weight of titanium oxide and fired to an average particle size of 0.8 μm was used. (2) Resin paint (% by weight) A polyester resin paint having the following composition was used. 30.6% polyester resin, 39.6% solvent, 26.5% titanium oxide coloring pigment, 1.5% titanium yellow, 2.6% silica matting agent

[Comparative Examples 1 to 3] As shown in the chart of FIG. 2, in Comparative Example 1, no antibacterial powder was added, and in Comparative Example 2, a silver-containing zeolite antibacterial agent was added. Was carried out in the same manner as in the above example, except that an imidazole organic antibacterial agent was added.

The coated steel sheet prepared as described above was subjected to an antibacterial test in the following manner.

[Antibacterial Test] An antibacterial test was carried out on fungi of black mold, blue mold and black yeast-like fungus, and on bacteria of Escherichia coli, Staphylococcus aureus and Salmonella. The test method for antibacterial activity was as follows.
Using the test bacteria cultured for 10 hours, the number of each test bacteria is 10
^After adjusting to ⁶ to 10 ⁷ cells / ml to form a test bacterial solution, 0.2 ml of the test bacterial solution was dropped onto filter paper, and the filter paper was allowed to stand on each test piece. In the case of, the 44th hour) Take out the filter paper left at each hour at the 144th hour, put it in 9.8 ml of sterilized water, take out 0.1 ml from it, smear it and culture it. The number of bacteria (cells / ml) was examined.

[Test Results] The results of the antibacterial test are as shown in FIG. However, in the chart, the ◎ mark indicates that the viable cell count is 10 ³
個 / ml or less, ○ indicates viable cell count of 10 ⁴ to 10 ⁵ / ml, Δ
The mark indicates a viable cell count of 10 ⁵ to 10 ⁶ cells / ml, and the X mark indicates a viable cell count of 1
0 and ⁶ cells / ml or more. As is clear from this chart, Comparative Example 3 in which an imidazole organic antibacterial agent was added.
In the case of the mold, even if the mold has an antibacterial effect, the antibacterial effect is low for the bacterium. In Comparative Example 2 in which a silver-containing zeolite-based antibacterial agent is added, only about 10 ⁶ to 10 ⁴ bacteria / ml are obtained. Although there is no decrease in the number, in Examples 1 to 5, it can be seen that both fungi and bacteria have an effect of reducing the number of bacteria over the silver-containing zeolite-based antibacterial agent over time.

[0017]

According to the present invention, far-infrared electromagnetic waves are radiated from antibacterial powder to resonate and excite water in bacterial cells forming general bacteria and water molecules of environmental moisture essential for their propagation. Therefore, the physiological function of the cells can be inhibited, and the growth of the cells can be effectively suppressed. In addition, since the average particle size of the antibacterial agent constituting the antibacterial powder is 1 μm or less and the surface area ratio is increased, the radiation efficiency of electromagnetic waves in the infrared region can be increased accordingly, and the propagation of bacteria is more effective. Can be suppressed.
The antibacterial powder does not deteriorate even when painted on a metal plate and baked at a high temperature. In particular, since titanium oxide is used, the sterilizing power can be increased. The antibacterial powder of the present invention does not elute the drug, but exhibits an antibacterial action by radiation of electromagnetic waves in the infrared region.
In particular, it can be used with confidence in kitchen utensils and the like that require food safety.

[Brief description of the drawings]

FIG. 1 is a schematic diagram used for explaining an antibacterial agent constituting an antibacterial powder of the present invention.

FIG. 2 is a table showing Examples 1 to 5 and Comparative Examples 1 to 3.

FIG. 3 is a table showing the results of an antibacterial test.

[Explanation of symbols]

 Reference Signs List 1 antimicrobial agent 2 silicon carbide or carbon oxide 3 aluminum oxide 4 titanium oxide

Claims (1)

[Claims] 1. An antibacterial agent having an average particle size of 1 μm or less,
The antibacterial agent is characterized in that the antibacterial agent is fired at a ratio of 30 to 80% by weight of silicon carbide or silicon oxide, 10 to 40% by weight of aluminum oxide, and 10 to 30% by weight of titanium oxide. powder.