JP3273130B2 - Method for producing antibacterial metal article and antibacterial metal article produced by the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an antibacterial metal article which does not require any change in a conventional method for manufacturing a metal article, and an antibacterial metal article manufactured by the method. In the present invention, the antimicrobial properties also mean antifungal properties and anti-algal properties, and metal articles are articles formed of metal, such as stainless steel sheets and metal articles such as aluminum sheets. I do.

[0002]

2. Description of the Related Art Recently, there has been proposed a metal article having antibacterial properties by using a metal having a so-called oligodynamic effect for suppressing the growth of bacteria such as silver and copper, fungi, algae and the like. For example, Japanese Unexamined Patent Publication No. 8-49085 discloses that a magnetron-sputtered C containing Ag and / or Cu is used.
A stainless steel sheet having excellent antibacterial properties in which a metal layer or an alloy layer of r, Ti, Ni, Fe, etc. is formed on the surface of the stainless steel sheet is disclosed.
It is stated that it is preferable to form a metal layer or an alloy layer containing 60% by weight of Ag.

[0003] Japanese Patent Application Laid-Open No. 9-176800 discloses C,
A method is described in which an austenitic stainless steel having a composition containing specific amounts of Si, Mn, Cr, Ni, and Cu is heat-treated in a temperature range of 500 to 900 ° C to obtain an austenitic stainless steel having antibacterial properties. Furthermore, for example, by adding a specific amount of Ag to a ferritic stainless steel raw material in which Si, Mn, P, Al, V, etc. are controlled in an appropriate range, and melting the material, workability, corrosion resistance,
A method for obtaining a ferritic stainless steel sheet having excellent antibacterial properties is also known.

[Problems] However, Japanese Patent Application Laid-Open No. 8-4908
The antibacterial stainless steel sheet described in Japanese Patent No. 5 has a problem that the layer containing the antibacterial metal is peeled or removed by drawing or polishing of the surface, and the effect cannot be expected. In this method, a metal layer or an alloy layer is formed on the surface of the stainless steel plate, so that the number of manufacturing steps is increased compared to the conventional method, and the surface properties of the stainless steel plate, for example, the color tone are changed. Further, in the austenitic stainless steel described in JP-A-9-176800 or the above-mentioned ferritic stainless steel sheet, an antibacterial component exists deep inside, and this component is resistant to bacteria, mold, and algae attached to the stainless steel surface. However, there is a problem that it is uneconomical because it has no effective effect.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the problems in the prior art, and an object set specifically to solve the problems is to use an antibacterial component with a metal. Manufacture of antibacterial metal articles that solve the above-mentioned economic problems by intensively distributing them to the surface layer of the article, and that do not consume antibacterial properties in a short period of time due to abrasion and the like, and that the surface properties do not significantly change. An object of the present invention is to provide a method and an antibacterial metal article manufactured by the method.

[0006]

Means for Solving the Problems Claim 1 of the present invention
The method for producing an antibacterial metal article according to the present invention is characterized by including a step of applying a fine particle dispersion or solution of an antibacterial component to the surface of the metal article and pressurizing the article under non-heating.

In a second aspect of the present invention, there is provided a method for manufacturing an antibacterial metal article, wherein a pressing force at the time of pressing is 1 kg / mm ² or more.

In a third aspect of the present invention, the antibacterial component is silver, copper, a silver-copper alloy, silver chloride, silver sulfide, silver oxide, silver sulfate, silver phosphate, or chloride. Cuprous,
Be at least one selected from cupric chloride, cuprous sulfide, cupric sulfide, cuprous oxide, cupric oxide, cuprous sulfate, cupric sulfate, and copper phosphate It is characterized by.

Further, the antibacterial metal article according to claim 4 is:
It is manufactured by the manufacturing method according to any one of claims 1 to 3.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. However, the embodiments are specifically described for better understanding of the present invention, and do not limit the contents of the invention unless otherwise specified.

The antibacterial metal article in this embodiment is one in which the antibacterial component is diffused from the metal surface directly into the metal surface layer without heating. In this case, in order to diffuse the antibacterial component without heating, the antibacterial treatment surface of the metal article is sufficiently washed to remove dirt, and the fine particle dispersion or solution of the antibacterial component (hereinafter referred to as coating) is applied to the metal surface. (Hereinafter referred to as a liquid), and a pressure treatment for applying pressure without heating is performed to diffuse the antibacterial component from the metal surface into the surface layer.

The antimicrobial component used in this case preferably has an oligodynamic effect and does not contain components remaining after pressurization, and is easily diffused into the surface layer of the metal article.
From the viewpoints of safety, surface properties of metal articles such as no influence on color tone, silver, copper, silver-copper alloy, silver chloride, silver sulfide, silver oxide, silver sulfate, silver phosphate, cuprous chloride, Cupric chloride, cuprous sulfide, cupric sulfide, cuprous oxide, cupric oxide, cuprous sulfate, cupric sulfate, at least one selected from copper phosphate is preferred is there.

[0013] The coating liquid is obtained by dispersing or dissolving fine particles of an antibacterial component in water or an organic solvent and improving the wettability to the surface of a metal article by using a surfactant in combination. It is suitable. The application method of the application liquid includes a spray method, a dipping method and the like, and there is no particular limitation. The concentration of the antibacterial component in the coating solution is preferably 0.01 to 10% by weight.
If it is thinner than this, sufficient antibacterial properties cannot be obtained, and if it is higher than this, stains due to antibacterial components often remain. The particle size of the antibacterial component in the coating solution is 10 μm or less, and particularly preferably 0.1 μm or less. When an antibacterial component having such a particle size is used, diffusion into the metal article surface layer is prevented. It happens easily.

The pressing force is not particularly limited, but is 1 kg.
/ Mm ² or more, particularly a degree to which the metal article is slightly deformed. The pressing time is not particularly limited, and may be short (instantaneous). The appropriate set pressure depends on the type of antimicrobial component used and the depth to which the antimicrobial component diffuses. Further, the pressing means is not particularly limited, for example, roll pressing, hydrostatic pressing, press method and the like can be used, especially the roll pressing method is suitable because it can be used without any change to the existing rolling process is there. The atmosphere at the time of pressurization is not particularly limited, and is usually performed in the air.

After the pressure treatment, undiffused components may remain on the surface of the metal article, which can be easily removed by acid washing or polishing. Since the antibacterial component is diffused into the surface layer portion of the metal article, the antibacterial property does not disappear or decrease even after removing the non-diffused components, and still has good antibacterial property.

Regarding the antibacterial property of the antibacterial metal article, it is considered that an antibacterial component exposed on the surface of the metal article exhibits the antibacterial property. For this reason, even if the surface of the metal article is worn or eroded, the internal antibacterial component is newly exposed, so that the antibacterial property does not decrease.

Further, since the metal layer or the alloy layer is not formed on the surface of the metal article, the surface properties of the metal article, such as the color tone, do not change. In addition, since the antibacterial component is diffused without heating, the antibacterial component does not deteriorate, has excellent antibacterial properties, and has little restrictions on production.

The metal article is not particularly limited, and may be a plate-like object such as a stainless steel plate, an iron plate, an aluminum plate, a copper plate, or the like.
Other arbitrary shaped metal products can be exemplified.
Further, as a pressing method, a roll pressing method can also be used, and since this method does not require any change to the existing rolling process, plate-like objects such as various metal plates are suitable as metal articles. .

As described above, according to the antibacterial metal article and the method of manufacturing the same according to the embodiment, since the antibacterial component is directly present inside the vicinity of the surface of the metal article, the economical problem of the conventional melting method is obtained. And technical problems such as peeling of the layer containing the antibacterial metal are eliminated.

[0020]

EXAMPLES Specific examples will be described below. Example 1 An aqueous dispersion of silver fine particles having an average particle diameter of 20 nm prepared by a known method was applied to a stainless steel sheet of SUS430 using a roll coater so that the coating amount was 0.1 g / m ^{2 of the} silver fine particles. did. Apply pressure at 25 ° C
10 kg / mm ² was added by a rolling roll to diffuse silver into the surface layer of the stainless steel plate. Thereafter, acid washing was performed with a 5% nitric acid aqueous solution to obtain an antibacterial stainless steel sheet.

The diffusion state of silver in the surface layer of this antibacterial stainless steel sheet was determined by the GDMS method (glow discharge mass spectrometry).
As a result, as shown in FIG.
The presence of 00 ppm of silver atoms was confirmed, and the presence of silver atoms was confirmed up to a depth of about 6 μm. Therefore, the antibacterial property does not disappear even with a little abrasion. Next, the antibacterial property of the antibacterial stainless steel sheet thus produced was evaluated by conducting an antibacterial property test in accordance with the “Film Adhesion Method” established by the Study Group for Inorganic Antibacterial Agents for Silver and Other Materials. Table 1 shows the results.

The outline of the film adhesion method is as follows.
Includes a nutrient broth diluted to 1/500 in "specimen, Escherichia coli was adjusted to a cell concentration of about 10 ⁵ cfu / ml, a bacterial solution of Staphylococcus aureus 25 cm ² and per 0.5ml inoculated, on the bacterial suspension Place a polyethylene film of the same shape as the test specimen, and incubate it at 35 ° C for 24 hours, and measure the number of viable bacteria by the agar plate method. ”

Example 2 An antibacterial aluminum plate was obtained in the same manner as in Example 1 except that an aluminum plate was used instead of the stainless steel plate. When the diffusion state of silver in the surface layer of the antibacterial aluminum plate was analyzed by the GDM method, the presence of about 500 ppm of silver atoms on the surface was confirmed, and the depth was about 1 ppm.
The existence of silver atoms was confirmed up to 0 μm. Next, the antibacterial properties of the thus prepared antibacterial aluminum plate were evaluated in accordance with Example 1. Table 1 shows the results.

Example 3 Example 1 was repeated except that a copper fine particle dispersion having an average particle diameter of 100 nm prepared by a known method was used.
An antibacterial stainless steel sheet was obtained according to When the state of diffusion of copper in the surface layer of the antibacterial stainless steel sheet was analyzed by the GDM method, the presence of about 350 ppm of copper atoms on the surface and the presence of copper atoms up to a depth of about 8 μm were confirmed. Next, the antibacterial property of the antibacterial stainless steel sheet thus manufactured was evaluated in accordance with Example 1. Table 1 shows the results.

[Comparative Example 1] SU without antibacterial treatment
The antibacterial property of the S430 steel sheet was evaluated according to Example 1. Table 1 shows the results. [Comparative Example 2] The antibacterial property of the aluminum plate used in Example 2 which was not subjected to the antibacterial treatment was evaluated in accordance with Example 1.
Table 1 shows the results.

[0026]

[Table 1]

As apparent from Table 1, Examples 1 to 3
The antimicrobial-treated metal articles of No. 5 had a viable cell count of less than 5, and a clear difference from the non-antimicrobial-treated plates of Comparative Examples 1 and 2 was confirmed.

[0028]

As described above, according to the present invention, in the method for producing an antibacterial metal article according to the first aspect, a fine particle dispersion or solution of an antibacterial component is applied to the surface of the metal article, and is heated without heating. By performing the pressure treatment, the antibacterial component can be easily diffused into the surface layer portion of the metal article, and excellent antibacterial property can be imparted to the metal article. Moreover, this manufacturing method is simple and can be used without any change in the conventional rolling process and the like, so that a metal article having excellent antibacterial properties can be easily manufactured.

In the method for producing an antibacterial metal article according to the second aspect, the pressing force at the time of pressing is set to 1 kg / mm ² or more, so that the antibacterial component is diffused deeper into the surface layer of the metal article. It is possible to produce an antibacterial metal article which does not lose its antibacterial property even if it is slightly worn.

Further, in the method for manufacturing an antibacterial metal article according to claim 3, the antibacterial component is silver, copper, silver-copper alloy, silver chloride, silver sulfide, silver oxide, silver sulfate, silver phosphate, silver chloride. Cuprous, cupric chloride, cuprous sulfide, cupric sulfide, cuprous oxide, cupric oxide, cuprous sulfate, cupric sulfate, at least one selected from copper phosphate By using the seed, the diffusibility into the inside of the metal article surface layer is good, the safety in use is high, and the surface properties of the metal article, such as the color tone, can be prevented from being adversely affected. .

The antibacterial metal article according to claim 4 is manufactured by the manufacturing method according to any one of claims 1 to 3, so that the antibacterial component is diffused into the surface of the metal article by heat treatment. Since the antibacterial component is not deteriorated, the antibacterial component is not deteriorated, and exhibits excellent antibacterial activity. Will not be.

[Brief description of the drawings]

FIG. 1 is a graph showing the concentration of an antibacterial component in a depth direction in a surface part of a metal article of Example 1.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Yokota 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Engineering Co., Ltd. (72) Inventor Susumu Suto 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba (56) References JP-A-8-73633 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 24/06 A61L 2/16

Claims (4)

(57) [Claims] 1. A dispersion or solution of fine particles of an antibacterial component,
A method for producing an antibacterial metal article, comprising a step of applying the composition to the surface of a metal article and applying pressure without heating. 2. The method for producing an antibacterial metal article according to claim 1, wherein the pressing force at the time of pressing is 1 kg / mm ² or more. 3. The antibacterial component is silver, copper, silver-copper alloy, silver chloride, silver sulfide, silver oxide, silver sulfate, silver phosphate, cuprous chloride, cupric chloride, cuprous sulfide, 3. The method according to claim 1, wherein the material is at least one selected from cupric sulfide, cuprous oxide, cupric oxide, cuprous sulfate, cupric sulfate, and copper phosphate. A method for producing an antibacterial metal article. 4. An antibacterial metal article manufactured by the manufacturing method according to claim 1.