| 摘要 |
A process for coloring metal flakes by dispersing the flakes in an inorganic metal oxide sol to coat the flakes with the sol, dispersing the sol-coated flakes in a solution of an inorganic metal compound in a solvent, and thereafter heating the flakes for producing thereon a sol-gel coating that imparts to the flakes a visible color different from the color of the metal flakes when uncoated. The sol, the compound and the solvent are mutually selected to form the color-providing sol-gel coating on the metal flakes upon heating. Aluminum flake pigments are colored in this manner using an aqueous alkaline zirconia sol and a solution of cobalt nitrate in ethanol and/or water or a solution of iron nitrate in ethanol (followed, in the case of iron nitrate, by a treatment with ammonium hydroxide in ethanol). The steps of successively dispersing the flakes in the sol and solution may be repeated to intensify the produced color. |
