| 摘要 |
PROBLEM TO BE SOLVED: To provide a recording liquid which enables high-quality printing to be obtained even on plain paper by dissolving, in an aqueous medium, an anionic water-soluble colorant and a cationic surfactant which can be bonded thereto to form an insoluble colorant. SOLUTION: Preferably, the anionic water-soluble colorant contains at least one kind of acidic group selected from sulfo, carboxyl, and phosphoric groups. A preferable example of the cationic surfactant has a tetraalkylammonium group of which at least one alkyl group has at least 8 carbon atoms, still preferably at least 14 carbon atoms, an especially preferable example being a quaternary ammonium salt having a 14C or higher alkyl group and 3 methyl groups, The surfactant is used in an equivalent ratio higher than 1 to the sum of the sulfo, carboxy, and phosphoric groups of the water-soluble colorant, Thus obtained recording liquid is an emulsion type one which has a good storage stability and gives recorded images having a high density and excellent hue and water resistance. |
