TREATMENT OF SURFACE OF ALUMINUM OR ALUMINUM ALLOY

PROBLEM TO BE SOLVED: To obtain an aluminum product having antibacterial properties with hardly requiring a new set of equipment by subjecting an aluminum material to anodic oxidation treatment, thereafter immersing it into hot water contg. metallic salt of silver or the like and furthermore executing sealing treatment. SOLUTION: Aluminum or an aluminum alloy is subjected to anodic oxidation treatment, is thereafter immersed into hot water contg. silver nitrate, copper nitrate, zinc nitrate, nickel nitrate or the like by about 0.1 to 10g/L and is moreover subjected to sealing treatment. Furthermore, as for the hot water treatent, the treating time is regulated to about 3 to 4hr in the case the temp. of the hot water is 70 deg.C, to about 10min in the case of 80 deg.C and to about 5min in the case of 90 deg.C. In this way, the antibacterial aluminum product is obtd. at a low production cost. Various coloring can be executed to anodically oxidized coating, and the color tone variation of the antibacterial aluminum product is made rich.