| 摘要 |
PURPOSE:To form a printed picture with water resistance, quick drying property and high resolution by a method wherein a cation surface active agent is impregnated into a recording medium and water-soluble direct and/or acid dyes are added to an aqueous ink. CONSTITUTION:A cation surface active agent (e.g. tetraalkylammonium salt such as cetyltrimethylammonium bromide) is applied in the form of an aquenous solution to at least the surface of a recording medium such as paper, for example, and impregnated thereinto. On the other hand, water-soluble direct dyes (for example, C.I direct black 4) and/or water-soluble acid dyes (e.g. C.I acid red) are added to the aqueous ink. Thus obtained aqueous ink is printed on the recording medium. By so doing, for example, -SO3Na group present in ink is coupled to surface active cations so as to form water-insoluble salt on the surface of the recording medium, thereby improving the water resistance of a printed picture. |
