| 摘要 |
PROBLEM TO BE SOLVED: To obtain a colored titanium grain stably colored in a specified color and reduced in mottling by specifying the conditions of flat front and rear of the colored grain, the shape of the peripheral part and the thickness of a titanium oxide film layer on the surface. SOLUTION: The inside of the colored titanium grain consists of metallic titanium, and the surface layer consists of a titanium oxide film. The flat front and rear of the grain are smoothed, the peripheral part is not rugged but smooth and has a scaly shape, and the thickness of the titanium oxide film layer on the surface is controlled to 25-200nm. Further, the diameter of the scale is controlled to <=30μm, the thickness to <=5μm and the aspect ratio to >=25, and the average diameter of the metallic titanium grains is preferably adjusted to <=5μm. Consequently, the thickness of the titanium oxide film layer is adjusted by appropriately selecting the oxidation condition, hence a desired color is exhibited, and a colored titanium grain excellent in brightness and improved in cleanness in coloration and uniformity in the coloring degree is obtained.
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