| 摘要 |
PURPOSE:To markedly enhance room decoloration resistance while maintaining excellent color forming properties, by recording in a water-based ink containing a water-soluble dye on a recording material in which the pH of a coating liquid for forming a pigment-containing coated layer on a base of the recording material is at least 7. CONSTITUTION:A coated layer provided on a base comprises a pigment and a water- based binder as main constituents, and is provided by using a coating liquid having a pH of at least 7. The pigment may be a silica pigment, which may be obtained by a method of adsorbing sodium on a silica pigment, a method wherein a metallic salt or a metallic soap is added to a suspended liquid containing a purified silica pigment to coat silanol groups at the surfaces of the pigment particles in a salt form, a method of incorporating a basic oxide into the crystal structure of a silica pigment, or the like. The coating liquid may also be obtained by a method of adding an alkali agent such as NaOH to an aqueous coating liquid containing a known pigment, or the like. A recording method is preferably an ink jet recording method, and a water-soluble dye as an essential constituent of an ink used is preferably a direct dye, an acid dye, a food dye or the like. The water-soluble dye is generally used by dissolving in water or a liquid medium comprising water and an organic solvent. |
