JPH10158889A - Light alloy excellent in antibacterial property and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light alloy excellent in antibacterial properties in which sufficient antibacterial properties are shown for a long time by a relatively small amt. of antibacterial components, there is no deterioration thereof even if sealing treatment is executed and there is no change in the color tone of the surface by diffusing inorganic antibacterial components into an anodic oxidation coating layer of a light alloy and dispersedly depositing them in a fine-grained shape. SOLUTION: Inorganic antibacterial components 3 are diffused into a layer of anodic oxidation coating 2 provided on the surface of a light alloy 1 such as an Al alloy, a Ti alloy or the like. As this inorganic antibacterial components, silver, copper, alloys and compounds thereof or the like are preferably used. In this way, a light alloy excellent in antibacterial properties is obtd. This light alloy can be obtd. by bringing the surface of a base material into contact with a dispersed soln. of an about 0.0001 to 10% degree of the fine grains of the inorganic antibacteriai components of about <=1μm, applying it by about 0.0001 to 1g/m<2> as the solid content, executing heating treatment at 100 to 600 deg.C to diffuse the fine grains therein and subjecting this surface layer to anodic oxidation treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light anti-microbial alloy having excellent antibacterial properties, which has an antibacterial effect for a long period of time and exhibits an effective antibacterial property even when a relatively small amount of an antibacterial substance is used. It relates to the manufacturing method. (Note that, in the present invention, the antibacterial property means the antifungal property and the antialgal property.)

[0002]

2. Description of the Related Art In recent years, with the growing trend toward hygiene and cleanliness, due to the spread of bacteria such as enterohemorrhagic Escherichia coli O-157 and MRSA, it is required to impart antibacterial properties to all kinds of materials. And other light alloys are no exception. As an antibacterial treatment method for imparting antibacterial properties to these light alloys, a coating containing various antibacterial agents has been applied to these surfaces.

[0003] Antibacterial agents used herein include organic antibacterial agents and inorganic antibacterial agents containing inorganic antibacterial components such as silver and copper. However, organic antibacterial agents have poor durability and are safe. Inorganic antimicrobial agents are preferably used because of their poor properties. On the other hand, as a method that does not use paint,
A method of depositing a metal such as silver in pores of an anodic oxide film of aluminum or an aluminum alloy is known (JP-A-58-167798).

[0004] In the case of applying a paint containing an antibacterial agent in the prior art, only the coating film on the surface has antibacterial properties, and the alloy itself does not have antibacterial properties. Accordingly, there is a problem that the antibacterial property is lost in a short time due to deterioration of the coating film, such as peeling and chalking.

In the method of depositing silver or the like in the fine pores of the anodic oxide film, the electrodeposition is performed from the deep part of the fine pores of the anodic oxide film, which has a disadvantage as shown in FIG. That is,
In the case where the amount of electrodeposition is small (see FIG. 3 (a)), antibacterial properties are hardly exhibited since silver and the like are deposited in the deep part of the fine pores. When a sealing treatment is performed to improve the corrosion resistance and weather resistance of the aluminum alloy (see FIG. 3B), the micropores are substantially closed, and the antibacterial property is lost. On the other hand, when the amount of electrodeposition is large (see FIG. 3 (c)), although the antibacterial property is developed, there is a problem that the coloring is remarkable and the design property of the antibacterial article is remarkably reduced. I was

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and an object of the present invention is to have an antibacterial property on the surface of the alloy and maintain the antibacterial effect for a long time. Light alloys that exhibit sufficient antibacterial properties even with a relatively small amount of inorganic antibacterial ingredients, have a small decrease in antibacterial properties even when subjected to sealing treatment, and have excellent antibacterial properties without change in surface color. It is to provide a manufacturing method thereof.

[0007]

Means for Solving the Problems Claim 1 of the present invention
The light alloy excellent in antibacterial property according to the above is characterized in that an inorganic antibacterial component is diffused in the anodic oxide film layer.

Further, the light alloy having excellent antibacterial properties according to claim 2 is characterized in that an inorganic antibacterial component is adsorbed on the anodized film layer in the form of fine particles.

A light alloy having excellent antibacterial properties according to claim 3 is characterized in that an aluminum alloy or a titanium alloy is used as a base material on which the anodic oxide film layer is provided.

Further, the method for producing a light alloy having excellent antibacterial properties according to claim 4 is characterized in that a fine particle dispersion of an inorganic antibacterial component is brought into contact with the surface of the light alloy, followed by heat treatment.
Fine particles of the inorganic antibacterial component are diffused into the surface layer of the light alloy, and then the surface layer is anodized.

Further, a method of manufacturing a light alloy having excellent antibacterial properties according to claim 5 is characterized in that the heat treatment is performed at a temperature of 100 to 600 ° C.

Further, according to a sixth aspect of the present invention, there is provided a method for producing a light alloy having excellent antibacterial properties, comprising: forming an anodic oxide film layer on the surface of the light alloy; The fine particles of the inorganic antibacterial component are adsorbed on the anodized film in the form of fine particles by contact with the anodized film.

Further, the method for producing a light alloy having excellent antibacterial properties according to claim 7 is characterized in that a sealing treatment is continuously performed.

Further, a method of manufacturing a light alloy excellent in antibacterial properties according to claim 8 is characterized in that an aluminum alloy or a titanium alloy is used as a base material on which the anodic oxide film layer is provided.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments of the present invention. However, this embodiment is specifically described for better understanding of the present invention, and does not limit the content of the present invention unless otherwise specified.

[Light alloy with antibacterial properties]
In the light alloy having excellent antibacterial properties, an inorganic antibacterial component is diffused in the anodic oxide film layer, and the inorganic antibacterial component is dispersed and supported in the form of fine particles. That is, as shown in FIG. 1, a large amount of the inorganic antibacterial component 3 is present in the anodic oxide film layer 2 provided on the light alloy 1 and is dispersed and supported in the form of fine particles. In the portion, the inorganic antibacterial component 3 is scarcely present, and further, the binder component and the fused film of the inorganic antibacterial component 3 are not substantially present on the surface of the light alloy. The antibacterial property is exhibited by the inorganic antibacterial component exposed on the surface of the anodic oxide film.

Therefore, even when the surface of the light alloy is slightly worn, a new inorganic antibacterial component is exposed, so that the antibacterial property does not disappear in a short time. The surface color is not significantly changed because it is not coated with chromium, and since the surface is anodized, sufficient corrosion resistance and
Has weather resistance.

The second antimicrobial light alloy of the present invention is:
Inorganic antibacterial components are adsorbed on the anodized film layer in the form of fine particles. That is, as shown in FIG. 2, a large amount of the inorganic antibacterial component 3 is present in the anodic oxide film layer 2 provided on the light alloy 1 and is adsorbed in the form of fine particles. Since a large number of holes are formed, it has a strong adsorptivity and the inorganic antibacterial component 3 is not easily desorbed.)
The inorganic antibacterial component 3 hardly exists in the central portion of the light alloy, and further, a film of the binder component and the inorganic antibacterial component 3 is not substantially formed on the surface of the light alloy.

Therefore, even when the surface of the light alloy is slightly worn, the antibacterial property does not disappear in a short time.
Further, since the surface of the light alloy is not coated with another material, the color tone of the surface is hardly remarkably changed. Further, since the surface is anodized, it has sufficient corrosion resistance and weather resistance.

Such light alloys having excellent first and second antibacterial properties include aluminum alloys, magnesium alloys, and titanium alloys. In particular, they are lightweight, high-strength, easily available, inexpensive and practical. An aluminum alloy or a titanium alloy, which is a material having excellent properties, is preferable. In the present invention, an aluminum alloy includes aluminum, a magnesium alloy includes magnesium, and a titanium alloy includes titanium.

[First Production Method] The first light alloy having excellent antibacterial properties of the present invention is produced by the following production method (hereinafter referred to as the first production method). First, the inorganic antibacterial component is diffused into the surface layer of the light alloy. That is, the fine particle dispersion of the inorganic antibacterial component is brought into contact with the desired surface of the light alloy and subjected to a heat treatment at a desired temperature to diffuse the fine particles of the inorganic antibacterial component into the surface layer of the light alloy.

Before the light alloy is brought into contact with the fine particle dispersion of the inorganic antibacterial component, the surface provided with antibacterial properties is sufficiently washed to remove dirt. As the inorganic antibacterial component that can be used, an organic or inorganic binder component (e.g., a glaze component) that is rich in heat resistance and has an oligodyne effect and remains after the heat treatment at the predetermined temperature. Etc.).

Suitable inorganic antibacterial components (in the present specification, the inorganic antibacterial component includes a simple metal having antibacterial properties) include a light alloy which is easily diffused into the surface layer portion; Silver, copper, silver-copper alloy, silver phosphate, silver chloride, silver sulfide, silver oxide, silver sulfate, silver citrate, silver lactic acid, and silver lactate have no effect on safety and surface properties (for example, color tone). And other organic silver compounds, silver-carrying inorganic compounds, cuprous phosphate, cupric phosphate, cuprous chloride, cupric chloride, cuprous sulfide, cupric sulfide, cuprous oxide, cupric oxide It is preferable to use one or more of copper copper, copper sulfate, copper sulfate, organic copper compounds such as copper citrate and copper lactate, and copper-supported inorganic compounds.

It is preferable that the fine particle dispersion of the inorganic antibacterial component is used in combination with a surfactant to improve the wettability to the light alloy. Methods for bringing the fine particle dispersion of the inorganic antibacterial component into contact with the light alloy include immersion, spray coating, brush coating, and the like, and are not particularly limited. The concentration of the fine particle dispersion of the inorganic antibacterial component is preferably 0.0001 to 10%. If the concentration is smaller than this, sufficient antibacterial properties cannot be obtained. If the concentration is higher than this, the film of the inorganic antibacterial component is formed on the light alloy surface. In many cases, they are formed or stains remain.

The coating amount of the inorganic antibacterial component is not particularly limited. For example, in the case of a silver-containing inorganic antibacterial component, it is preferably about 0.0001 to 1 g / m ^{2 in} terms of silver solid content.
If the amount is less than this, the antibacterial property is not sufficient, and if it is more than this, improvement in the antibacterial property cannot be expected. Further, the average particle diameter of the fine particles of the inorganic antibacterial component is preferably 1 μm or less, and particularly preferably a colloid of 0.1 μm or less. When the fine particles of the colloidal inorganic antibacterial component are used, the diffusion of the light alloy to the surface layer easily occurs.

The heat treatment temperature can be used in a wide range depending on the diffusion state of the antibacterial material into the base material.
600 ° C. is practically preferred. This is because the diffusion rate of the inorganic antibacterial component is slow at a temperature lower than 100 ° C, and the physical property change of the aluminum alloy or the titanium alloy becomes large at a temperature higher than 600 ° C. However, when the physical properties change due to the heating, there is no problem even if processing such as rolling or bending is appropriately performed.

The heating time is determined by the type of the inorganic antibacterial component to be used and the depth of diffusion of the inorganic antibacterial component, but usually 24 hours or less is sufficient. The atmosphere during the heat treatment is not particularly limited. Also, during the heat treatment,
Although there is no particular need to apply pressure, the application of pressure can shorten the heat treatment time and can further deeply diffuse.

Next, an anodic oxidation treatment is performed. For the anodic oxidation treatment, a known method can be applied. That is, in the case of anodizing treatment of an aluminum alloy, for example, an inorganic acid such as sulfuric acid, phosphoric acid, and chromic acid, or an organic acid such as oxalic acid, sulfosalicylic acid, and malonic acid; or sodium hydroxide, trisodium phosphate, and the like. In the alkaline aqueous solution of the above, a method of performing electrolysis by direct current, alternating current, pulse, or the AC / DC superposition method can be employed.

In the case of anodizing treatment of a titanium alloy,
For example, it is possible to employ a method of performing electrolysis in an aqueous solution of sulfuric acid, phosphoric acid, boric acid, acetic acid, or a salt thereof by a direct current, an alternating current, a pulse, or an AC / DC superposition method.

In the case of the anodic oxidation treatment of a magnesium alloy, the method described in MIL-M-45202A and MIL-M-3171A can be adopted. The oxide film formed by such anodizing treatment is stabilized, and imparts corrosion resistance, weather resistance, and the like to the light alloy.

Further, in the case of an aluminum alloy, the anodic oxide film can be colored by an electrolytic coloring method or a dyeing method following the anodic oxidation treatment. In other words, since the anodized film before the sealing treatment is porous and has a very large surface area, it is colored by depositing a metal in these holes or by adsorbing a dye utilizing this strong adsorptivity. Is what you do.

Next, a sealing treatment is performed as required. Known methods can be applied to the sealing treatment.
That is, it is not usually performed in the case of titanium alloys and magnesium alloys, but in the case of aluminum alloys, it is immersed in an aqueous solution of boiling water, a metal salt such as cobalt acetate or nickel fluoride, or exposed to pressurized steam. Can be performed.

It is to be noted that even without such a special sealing treatment, the sealing can be naturally performed by the water vapor contained in the air. Such a sealing treatment is preferable because the corrosion resistance and weather resistance of the light alloy are further improved, and the inorganic antibacterial component is not closed as shown in FIG. 3-2. The properties are not significantly reduced.

[Second Production Method] The light alloy of the present invention having excellent antibacterial properties is produced by the following production method (hereinafter, referred to as a second production method). First, the light alloy is anodized. As the anodic oxidation treatment, the anodic oxidation treatment in the first manufacturing method can be employed as it is.
In the case of an aluminum alloy, it is also possible to color the anodized film by an electrolytic coloring method or a dyeing method, following the anodizing treatment in the same manner as in the first manufacturing method.

Then, the fine particles of the inorganic antibacterial component are adsorbed on the surface of the anodic oxide film by bringing the fine particles of the inorganic antibacterial component into contact with the anodic oxide film layer formed by the anodic oxidation treatment. Before the anodized light alloy is brought into contact with the fine particle dispersion of the inorganic antibacterial component, the surface provided with antibacterial properties is sufficiently washed to remove dirt.

As the inorganic antibacterial component that can be used, the inorganic antibacterial component in the first production method can be used. It is preferable that the fine particle dispersion of the inorganic antibacterial component is used in combination with a surfactant to improve the wettability to the light alloy. Methods for bringing the fine particle dispersion of the inorganic antibacterial component into contact with the light alloy include immersion, spray coating, brush coating, and the like, and are not particularly limited.

The concentration of the fine particle dispersion of the inorganic antibacterial component is
0.0001 to 10% is preferable. If the thickness is less than this, sufficient antibacterial properties cannot be obtained. If the concentration is more than this, dirt often remains on the light alloy surface. The amount of adsorption of the inorganic antibacterial component is not particularly limited. For example, in the case of a silver-containing inorganic antibacterial component, it is preferably about 0.0001 to 1 g / m ^{2 in} terms of silver solid content, This is because the antibacterial properties are not sufficient, and improvement of antibacterial properties cannot be expected with more than this. Further, the average particle diameter of the fine particles of the inorganic antibacterial component is preferably 1 μm or less, and particularly preferably a colloid of 0.1 μm or less. When the colloidal fine particles of the inorganic antibacterial component are used, the adsorption to the anodic oxide film layer easily occurs.

Next, a sealing process is performed if necessary. Known methods can be applied to the sealing treatment.
In other words, titanium alloys and magnesium alloys are not usually used, but aluminum alloys are immersed in boiling water, an aqueous solution of a metal salt such as cobalt acetate or nickel fluoride, or exposed to pressurized steam. Can be performed. In addition, even if it does not perform the above-mentioned special sealing process, it is also possible to make it seal naturally with the water vapor contained in air. Such a sealing treatment is preferable because the corrosion resistance and the weather resistance of the aluminum alloy are further improved.
Since it is not closed as in (b), the antibacterial property is not remarkably reduced by the sealing treatment.

[0039]

【Example】

[Preparation of Sample] First, fine particle dispersions of the inorganic antibacterial component used in this example were prepared by the following three methods. (1) A silver nitrate aqueous solution of 0.2% by weight was placed in an evaporating dish, and a burner flame was applied to the liquid surface to obtain silver fine particles. This was dispersed in water to obtain a dispersion containing 0.1% by weight of silver fine particles. The average particle diameter of the silver fine particles was 0.01 μm. (2) One liter of water was added to 10 g of silver lactate, and the mixture was pulverized by a ball mill for 48 hours to obtain a 1% by weight dispersion of silver lactate. The average particle size of the silver lactate fine particles was 0.1 μm. (3) 0.5% by weight colloidal silica dispersion 100 cm ³
Was added 0.05 g of silver nitrate and 0.01 g of formaldehyde,
Ultraviolet irradiation was performed for 24 hours to obtain a fine particle dispersion in which silver was precipitated on the silica surface. The average particle size of the fine particles was 0.05 μm.

[Examples 1 to 3] The aluminum alloy 5052 plate material degreased with a solvent was immersed in the above-mentioned (1) to (3) silver or silver-containing particle dispersions, applied, and dried. The coating amount is 0.005, 0.03,
It was 0.001 g / m ² . Next, the plate was placed in air for 200
By heating at 8 ° C. for 8 hours, silver or a silver-containing substance was diffused into the surface layer of the aluminum alloy plate. Further, in a sulfuric acid solution having a concentration of 180 g / liter, the plate was used as an anode at 25 ° C. at a current density of 1.5 A / dm ² for 25 minutes to form an anodic oxide film having a thickness of 11 μm. afterwards,
Sealing treatment was performed by immersing for 5 minutes in an aqueous solution in which nickel acetate was dissolved to a concentration of 5 g / liter. No change was observed in any of the surface colors of this plate material.

[Comparative Example 1] A plate material of aluminum alloy 5052, which had been degreased with a solvent in the same manner as in Examples 1 to 3, was not immersed in a fine particle dispersion of silver or a silver-containing material and applied.
Heated at 200 ° C for 8 hours in air. Then, Examples 1-3
Anodizing treatment and sealing treatment were performed according to

Examples 4 to 6 Pickled industrial pure titanium plates were immersed in the above-mentioned (1) to (3) silver or silver-containing particle dispersions, applied, and dried. The coating amounts were 0.005, 0.03, and 0.001 g / m ² in terms of silver, respectively. Next, this plate is heated at 450 ° C for 1 hour in the atmosphere,
Silver or a silver-containing material was diffused into the surface layer of the plate material. Further, a mixture of phosphoric acid and sulfuric acid (phosphoric acid concentration: 25 g / liter,
(Sulfuric acid concentration: 35 g / liter) At 25 ° C, this plate is used as an anode, and the voltage is raised to 250 V at a temperature of 15 V / min, and then a constant voltage electrolysis is performed for 30 minutes to form a 6 μm thick anodic oxide film. did. Thereafter, no special sealing treatment was performed, and the device was left in the air. No change was observed in any of the surface colors of this plate material.

[Comparative Example 2] A plate made of titanium, which had been pickled in the same manner as in Examples 4 to 6, was heated at 450 ° C for 1 hour in the air without being immersed and coated in a fine particle dispersion of silver or a silver-containing material. did. Thereafter, according to Examples 4 to 6, an anodic oxidation treatment was performed. Thereafter, no special sealing treatment was performed, and the device was left in the air.

Examples 7 to 9 A plate of aluminum alloy 5052 degreased with a solvent was placed in sulfuric acid having a concentration of 180 g / liter at 25 ° C., and the plate was used as an anode at 1.5 A / d.
It performed 25 minutes electrolysis at a current density of m ^2, a thickness of 11 mu
m of the anodic oxide film was formed. Next, the silver or silver-containing fine particle dispersion of (1) to (3) was cooled to 10 ° C.
After being immersed and applied for a minute, it was dried. The adsorption amount was 0.005, 0.03, and 0.001 g / m ² in terms of silver, respectively. Subsequently, sealing treatment was performed by immersion in ion exchanged water at 95 ° C. for 5 minutes. No change was observed in any of the surface colors of this plate material.

[Comparative Example 3] An aluminum alloy 5052 plate material degreased with a solvent in the same manner as in Examples 7 to 9 was subjected to anodizing treatment and sealing treatment according to Examples 7 to 9 (silver or silver). No immersion or application of silver-containing material in fine particle dispersion).

COMPARATIVE EXAMPLE 4 A plate material of aluminum alloy 5052 which had been degreased with a solvent in the same manner as in Examples 7 to 9 was anodized in accordance with Examples 7 to 9. Then 15
g / l sulfuric acid, 1.5g / l silver nitrate bath 1
Electrodeposition was carried out under the conditions of 8 V so that the amount of silver deposited was 0.03 g / m ^2, and then the pores were sealed according to Examples 7 to 9.
A change was observed in the surface color tone of this plate material.

[Examples 10 to 12] A mixed solution of phosphoric acid and sulfuric acid (phosphoric acid concentration: 25 g / l, sulfuric acid concentration: 35 g / l) was prepared by using a pickled industrial pure titanium plate as an anode.
Medium, increase the voltage to 250V at a rate of 15V / min, then
A constant voltage electrolytic treatment was performed for 30 minutes to form an anodic oxide film having a thickness of 6 μm. After that, it was cooled to 10 ° C.
(3) dipping in silver or a silver-containing substance fine particle dispersion for 5 minutes,
After application, it was dried. The amount of adsorption is silver equivalent,
^They were 0.005, 0.03 and 0.001 g / m ² . Thereafter, no special sealing treatment was performed, and the device was left in the air. No change was observed in any of the surface colors of this plate material.

[Comparative Example 5] An industrial pure titanium plate material pickled in the same manner as in Examples 10 to 12 was used as an anode to produce Example 10.
Anodizing treatment was performed according to the method described in No. 12 above, and immersion, application, and special sealing treatment of silver or a silver-containing substance in a fine particle dispersion were not performed, and the mixture was left in the air.

"Antibacterial test" The antibacterial properties of the samples prepared in Examples 1 to 12 and Comparative Examples 1 to 5 were evaluated in accordance with the film adhesion method established by the Research Committee on Inorganic Antibacterial Agents for Silver and Other Materials. did. The results are shown in the table. The outline of the test method of the film adhesion method is as follows. A 25 cm ² plate specimen was inoculated with 0.5 ml of a bacterial solution containing E. coli and Staphylococcus aureus containing a normal broth diluted to 1/500 and adjusted to a bacterial concentration of about 10 ⁵ cfu / ml. A polyethylene film of the same shape as the specimen is placed on the sample. After culturing this at 35 ° C for 24 hours, the number of viable bacteria is measured by the agar plate method. "

[0050]

[Table 1]

According to the antibacterial test results shown in the table, the viable cell count was 1 for the light alloys subjected to the antibacterial treatment of Examples 1 to 12.
While it decreased to below 00 (representing below the detection limit),
In the light alloys of Comparative Examples 1, 2, 3, and 5 which were not subjected to the antibacterial treatment, and the aluminum alloy which was subjected to the antibacterial treatment by the conventional electrodeposition method of Comparative Example 4, survival of many bacteria was observed. Was done. Accordingly, it was confirmed that the light alloy according to the present invention had an excellent antibacterial effect.

In addition, the light alloy according to the present invention has the same or smaller amount of silver carried than the aluminum alloy which has been subjected to the antibacterial treatment by the conventional electrodeposition method of Comparative Example 4 even though the amount of silver carried is the same or a small amount. Excellent in antibacterial properties. The reason is that
In the light alloy according to the present invention, silver is dispersed in fine particles.
The surface area of silver exhibiting an antibacterial action is very large and rich in activity because it is carried (Examples 1 to 6) or dispersed and adsorbed in fine particles (Examples 7 to 12). In the aluminum alloy having been subjected to the antibacterial treatment by the conventional electrodeposition method of Comparative Example 4,
It is also presumed that silver which exerts an antibacterial action has a small surface area and is not rich in activity because it is electrodeposited.

[0053]

As described above, according to the present invention, in the light alloy according to the first aspect, the inorganic antibacterial component diffuses in the anodic oxide film layer and is dispersed and supported in the form of fine particles. Extremely large and highly active, exhibiting sufficient antibacterial properties even with a relatively small amount of inorganic antibacterial components, with little decrease in antibacterial properties even after sealing treatment, and when the surface is slightly worn However, since the new inorganic antibacterial component is exposed, the antibacterial effect is maintained for a long period of time, and furthermore, an excellent effect that the surface tone is not changed since the surface is not coded by another material is produced.

In the light alloy according to the second aspect,
Since the inorganic antibacterial component is adsorbed on the anodized film layer in the form of fine particles, the surface area is very large and rich in activity.
Even with a relatively small amount of inorganic antibacterial component, it exhibits sufficient antibacterial properties, and even if sealing treatment is applied, there is little decrease in antibacterial properties, and even if the surface is slightly worn, a new inorganic antibacterial component can be used. Because of the exposure, the antibacterial effect is maintained for a long period of time. Further, since the surface is not coated with another material, an excellent effect that the surface tone does not change is produced.

In the light alloy according to the third aspect, the base material on which the anodic oxide film layer is provided is made of an aluminum alloy or a titanium alloy, so that the material is lightweight, has high strength, is easily available, and is inexpensive. It is possible to supply highly practical and excellent antibacterial products.

Further, in the method for producing a light alloy according to claim 4, the fine particles of the inorganic antibacterial component are brought into contact with a surface of the light alloy by contacting with a fine particle dispersion of the inorganic antibacterial component, and then heating. Was diffused into the surface layer of the light alloy, and thereafter, the surface layer was subjected to anodizing treatment, so that the inorganic antibacterial component was diffused to a deep metal by a simple method even for a dense metal such as a light alloy. Can be
Moreover, since the inorganic antibacterial component is dispersed and supported in the form of fine particles, the surface area is very large and rich in activity, so the amount of the inorganic antibacterial component used is reduced, and even with a relatively small amount of the inorganic antibacterial component. A light alloy exhibiting sufficient antibacterial properties can be easily manufactured.

Further, in the method for producing a light alloy according to the fifth aspect, the heat treatment temperature is set at 100 to 600 ° C.
The diffusion rate of the inorganic antibacterial component is relatively high, and the light alloy can be diffused to the target surface layer while the physical properties of the light alloy are not changed much.

In the method for producing a light alloy according to claim 6, an anodic oxide film layer is formed on the surface of the light alloy, and a fine particle dispersion of an inorganic antibacterial component is brought into contact with the anodic oxide film layer. By doing so, since the fine particles of the inorganic antibacterial component are to be adsorbed to the anodized film in the form of fine particles, the inorganic antibacterial component can be adsorbed to the anodized film in a fine particle form by a simple method, In addition, since the inorganic antibacterial component has a very large surface area and is highly active, the amount of inorganic antibacterial component used is reduced, and a light alloy that exhibits sufficient antibacterial properties even with a relatively small amount of inorganic antibacterial component is used. It can be easily manufactured.

Furthermore, in the method for manufacturing a light alloy according to the seventh aspect, since the sealing treatment is further performed, the surface of the light alloy can be stabilized, and more corrosion and weather resistance can be imparted.

Further, in the method for manufacturing a light alloy according to the eighth aspect, the base material on which the anodic oxide film layer is formed is an aluminum alloy or a titanium alloy, so that the material is lightweight, has high strength, and is easily available. Inexpensive and practical products with excellent antibacterial properties can be manufactured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a distribution state of an inorganic antibacterial component in a first light alloy having excellent antibacterial properties of the present invention.

FIG. 2 is a cross-sectional view schematically illustrating a distribution state of an inorganic antibacterial component in a second light alloy having excellent antibacterial properties of the present invention.

FIG. 3 is a cross-sectional view schematically showing an electrodeposition state of an inorganic antibacterial component in an aluminum alloy obtained by a conventional electrodeposition method. FIG. )
Indicates the case where the sealing treatment is performed after the electrodeposition, and (c) indicates the case where the amount of the electrodeposition is large.

[Explanation of symbols]

 1 Light alloy 2 Anodized film 3 Inorganic antibacterial component

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsutomu Usami 5-11-3 Shimbashi, Minato-ku, Tokyo Sumitomo Light Metal Industries Co., Ltd.

Claims (8)

[Claims] 1. A light alloy excellent in antibacterial properties, characterized in that an inorganic antibacterial component is diffused in an anodic oxide film layer. 2. A light alloy having excellent antibacterial properties, wherein an inorganic antibacterial component is adsorbed on the anodic oxide film layer in the form of fine particles. 3. The light alloy according to claim 1, wherein an aluminum alloy or a titanium alloy is used as a base material on which the anodic oxide film layer is provided. 4. A method in which a fine particle dispersion of an inorganic antibacterial component is brought into contact with the surface of a light alloy, and then heat treatment is performed to diffuse the fine particles of the inorganic antibacterial component into the surface layer of the light alloy. And then anodizing the surface layer to produce a light alloy having excellent antibacterial properties. 5. The method according to claim 4, wherein the heat treatment is performed at a temperature of 100 to 600 ° C. 6. An anodic oxide film layer is formed on a surface of a light alloy,
By contacting a fine particle dispersion of the inorganic antibacterial component with the anodic oxide film layer, the fine particles of the inorganic antibacterial component are adsorbed to the anodic oxide film in the form of fine particles. Light alloy manufacturing method. 7. The method for producing a light alloy having excellent antibacterial properties according to claim 4, wherein a sealing treatment is continuously performed. 8. The method according to claim 4, wherein an aluminum alloy or a titanium alloy is used as a base material on which the anodic oxide film layer is provided.