JP5915466B2 - Aluminum material manufacturing method - Google Patents

Description

  The present invention relates to an aluminum material having antibacterial properties imparted to its surface by iodine and a method for producing the same.

  Antibacterial properties are imparted to the anodized film by allowing iodine or an iodine compound to be present in the fine pores of the anodized film of the aluminum material and in the sealing generation part (Patent Documents 1 and 2). In Patent Documents 1 and 2, various inorganic and organic compounds are exemplified as the iodine compound, but in the examples, polyvinylpyrrolidone iodine (hereinafter sometimes referred to as PVPI) is used as the iodine compound.

JP 2000-54194 A JP-A-2005-350741

  The antibacterial property and durability of the aluminum material are improved by increasing the amount of iodine in the fine pores of the anodic oxide film and the seal formation part, but the color generated in the anodic oxide film becomes deeper as the amount of iodine increases. Therefore, when the aluminum material has a light achromatic or light-colored appearance, increasing the amount of iodine in the fine pores of the anodized film and the seal generation part will change the original color of the aluminum material and impair the appearance. There is.

  The present invention relates to an aluminum material that has a large amount of iodine or iodine compound in the fine pores of the anodized film and in the seal generation part, and that is less colored by iodine or iodine compound, and can have a good appearance, and a production method therefor The purpose is to provide.

The method for producing an aluminum material of the present invention is an aluminum material having an anodized film, and iodine and / or an iodine compound present as iodine in an amount of 10 to 100 mg / cm ^{3 in the} fine pores of the anodized film and in the sealing generation part. The lightness L ^* of at least a part of the surface is 40 to 90, and the color difference ΔE ^* ab of the surface before and after the treatment when the iodine volatilization treatment is performed by heating at 250 ° C. for 4 hours in the atmosphere. Is a method for producing an aluminum material having an anodic oxide film of 3 or less, wherein the anodized film contains iodine and / or an iodine compound by immersing an aluminum base material having an anodized film in an iodine compound aqueous solution at a temperature of 85 ° C. or higher. have a step of the iodine compound is trimethyl sulfoxonium iodide and / or trimethylsulfonium iodide, pH of the iodine compound solution is 4.5 to .0 is an der shall.

  The aluminum material provided by the present invention is excellent in antibacterial property, antifungal property, and antiviral property because the amount of iodine and / or iodine compound in the fine pores of the anodic oxide film and in the sealed portion is large. Furthermore, the aluminum material of the present invention is excellent in antimicrobial effect persistence. This is probably due to the chemical bond between aluminum and iodine. Moreover, even if this aluminum material contains many iodine and / or iodine compounds, there is little coloring by iodine and / or an iodine compound, and it is excellent in aesthetics.

  Hereinafter, the present invention will be described in detail.

The aluminum material of the present invention has an anodized film on at least a part of its surface, and iodine and / or an iodine compound is present as 1 to 100 mg / cm ³ as iodine in the fine pores and the pore generation part. This iodine and / or iodine compound-containing anodic oxide film may be present on the entire surface of the aluminum material, or may be present only on a part, for example, the surface to be the product surface.

  The base material of the aluminum material is made of aluminum or an aluminum alloy, and examples thereof include, but are not limited to, JIS 1000 series, 3000 series, 5000 series, and 6000 series.

  The substrate is preferably first degreased and washed with acid, then washed with water, and subjected to an alkali etching treatment. Next, it is washed with water, neutralized, washed again with water, and then anodized.

The anodic oxidation treatment can be performed by a conventional method, and an anodized film is formed by energizing the molded body as an anode in a treatment bath. The type of treatment bath and the treatment conditions in the anodizing treatment are not limited to specific ones. Suitable conditions for the anodizing treatment are exemplified below.
Electrolytic voltage: 5 to 20 V (particularly preferably 10 to 15 V)
Current density: 0.5 to 3.0 A / dm ² (particularly preferably 1.0 to 2.0 A / dm ² )
Electrolytic solution: 10 to 20% by weight sulfuric acid solution (particularly preferably 12 to 18% by weight)
Electrolysis temperature: 10 to 30 ° C. (particularly preferably 15 to 25 ° C.)

  Although the thickness of the anodic oxide film obtained by the above is not specifically limited, For example, it is about 3-25 micrometers.

  After this anodizing treatment, washing with water is performed, and then an impregnation treatment with an iodine compound is performed to allow iodine and / or iodine compound to exist in the fine pores of the anodized film and in the sealing portion.

Examples of the iodine compound include trimethylsulfoxonium iodide ((CH ₃ ) ₃ IOS. Hereinafter, sometimes referred to as TMSOI) and / or trimethylsulfonium iodide ((CH ₃ ) ₃ IS, hereinafter referred to as TMSI. May be mentioned).

  To impregnate the anodic oxide film with this iodine compound, the iodine compound concentration is preferably 1 to 100 g / L (especially 10 to 50 g / L), the temperature is 85 ° C. or higher, particularly 95 to 100 ° C., pH 4.5 to 7.0. Immerse in a bath (adjusted with pH adjuster) for 5-30 minutes, especially 10-20 minutes, and then wash with water.

  According to this method, the pores of the anodized film are sealed, elution of iodine and / or iodine compounds is suppressed, and the durability of the antibacterial effect is improved. Further, the sealing improves the corrosion resistance and stain resistance of the anodized film.

  When the concentration of the iodine compound aqueous solution is lower than 1 g / L, the treatment time for increasing the iodine content of the anodized film is excessively long. When the concentration is higher than 100 g / L, there is no change in imparting antibacterial properties. In addition, there is a possibility of incurring an economic loss such as an increase in chemical cost due to taking out the processing liquid from the product to be processed.

  This is because if the temperature of the iodine compound aqueous solution is lower than 85 ° C., the time until the pores of the anodized film are sealed becomes excessively long.

  This is because when the pH of the iodine compound aqueous solution is outside the range of 4.5 to 7.0, the corrosion resistance decreases due to dissolution of the anodized film.

  This method has a small number of steps, can be easily performed, and is low in cost.

Content in the anodic oxide film micropores per unit volume and sealing generator of iodine and / or iodine compound is preferably 1 to 100 mg / cm ³ particularly 10-100 mg / cm ³ as iodine. If the content of iodine and / or iodine compound is less than the above range, the antibacterial property of the aluminum material will be low, and if it is more than the above range, the anodized film will be darkly colored or the color difference before and after the iodine volatilization treatment Becomes larger.

In the present invention, the color difference ΔE ^* ab on the surface of the anodic oxide film before and after the treatment when the aluminum material is heated at 250 ° C. for 4 hours in the atmosphere and subjected to the iodine volatilization treatment is 3 or less, preferably 2 or less. Thus, a small change in the color difference before and after the iodine volatilization treatment means that there is little coloring by iodine, and the aluminum material of the present invention has an appearance despite containing a large amount of iodine and / or iodine compound. Excellent aesthetics above. The effect of the present invention is particularly remarkable in the case of an aluminum material having a light-colored appearance with a lightness L ^* of 40 or more, preferably 60 or more.

  Aluminum may be any of a shape material, a panel material, a cast product, and the like. The aluminum product may be any of building materials, furniture, vehicles, daily necessities, sports equipment, machinery and equipment.

  Hereinafter, examples and comparative examples will be described.

[Example 1]
An aluminum material (JIS6063 material, 170 × 60 × 2 mm) that has been subjected to degreasing, etching, and neutralization treatment is subjected to an anodizing treatment by supplying electricity for 120 A / m ² × 1630 seconds in a sulfuric acid bath of 170 g / L of sulfuric acid. An anodic oxide film having a film thickness of 10 μm was formed on the entire outer surface. Next, the aluminum material was immersed in a TMSOI aqueous solution having a TMSOI concentration of 50 g / L, a temperature of 95 ° C., and a pH of 5.0 (adjusted with acetic acid and sodium acetate) for 20 minutes, then taken out, washed with water and dried to obtain an aluminum material. Manufactured.

  With respect to this aluminum material, the iodine content in the fine pores of the anodized film and in the sealed portion was measured by the following method.

<Measurement Method of Iodine Content in Anodic Oxide Film Micropores and Seal Generation Part>
The iodine and / or iodine compound-containing anodic oxide film is dissolved with a 10 g / L sodium hydroxide aqueous solution, and iodine ions contained in this aqueous solution are iodine-moleculed by an oxidizing agent. Iodine molecules in this aqueous solution were separated and extracted with a chloroform solvent, and then measured using absorptiometry.

  Further, the antibacterial properties of this aluminum material were measured according to the following method.

<Antimicrobial test method>
As an antibacterial evaluation, E. coli (NBRC 3972) was used, and an antibacterial test was conducted by a film adhesion method. A test bacterial solution was prepared by suspending a test bacterium in a normal bouillon medium having a concentration of 1/500 and adjusting it to 2.5 to 10 × 10 ⁵ cells / ml. A test piece cut to 50 mm × 50 mm was placed in a petri dish, and 0.4 ml of a test bacterial solution was dropped onto the test piece. A sterilized film (40 mm × 40 mm) was covered from above, cultured at 35 ° C. and a humidity of 90% or more for 6 hours, and the viable cell count was measured.

  Moreover, the sealing degree test (admittance measurement) was implemented about this aluminum material based on JISH8683-3.

Further, the lightness L ^* of this aluminum material and the color difference ΔE ^* ab before and after the iodine volatilization treatment in the atmosphere at 250 ° C. for 4 hours were measured using a colorimeter. These measurement results are shown in Table 1.

[ Comparative Example 4 ]
In Example 1, an aluminum material was manufactured in the same manner except that the TMSOI concentration was changed to 10 g / L. The measurement results are shown in Table 1.

[ Comparative Example 5 ]
In Example 1, an aluminum material was manufactured in the same manner except that the pH of the TMSOI aqueous solution was changed to 6.0. The measurement results are shown in Table 1.

[Comparative Example 1]
In Example 1, an aluminum material was manufactured in the same manner except that pure water was used instead of the TMSOI aqueous solution. The measurement results are shown in Table 1.

[Comparative Example 2]
In Example 1, an aluminum material was manufactured in the same manner except that the temperature of the TMSOI aqueous solution was changed to 75 ° C. The measurement results are shown in Table 1.

[Comparative Example 3]
In Example 1, an aluminum material was produced in the same manner except that a PVPI aqueous solution having a concentration of 10 g / L was used instead of the TMSOI aqueous solution. The measurement results are shown in Table 1.

As shown in Table 1, the aluminum material of the present invention is excellent in antibacterial properties, has a small color difference ΔE ^* ab before and after the iodine volatilization treatment (small coloring due to iodine content), has a low admittance value, and a high sealing degree.

Claims (1)

An aluminum material having an anodic oxide film, wherein iodine and / or iodine compound is present as iodine in 10-100 mg / cm ^{3 in the} pores of the anodic oxide film and in the sealed pores ;
The lightness L ^* of at least a part of the surface is 40 to 90, and the surface color difference ΔE ^* ab before and after the treatment when the iodine volatilization treatment is performed by heating at 250 ° C. for 4 hours in the air is 3 or less. a method of manufacturing an aluminum material is,
The aluminum substrate having the anodized film is immersed in an iodine compound aqueous solution over a temperature 85 ° C. have a step of containing iodine and / or iodine compound in the anodized film,
The iodine compound is trimethylsulfoxonium iodide and / or trimethylsulfonium iodide,
Method for producing a pH of 4.5 to 7.0 der Ru aluminum material of the iodine compound solution.