A water base ink for ink-jet recording is provided, which makes it possible to perform the discharge operation stably and highly accurately for a long period of time without deteriorating a metal, for example, due to corrosion and/or dissolution even when the ink makes contact with the metal composed of nickel or an alloy containing nickel for a long period of time. The water base ink for ink-jet recording is usable for an ink-jet recording apparatus provided with an ink-jet head having a metal member which is composed of nickel or the alloy containing nickel and which is disposed at least in an ink supply passage for supplying the ink to a discharge section. The water base ink for ink-jet recording contains potassium p-tert-butylbenzoate, a coloring agent which is dispersible or soluble in water, water, and a water-soluble organic solvent.
An ink for ink-jet recording is provided in which C. I. Direct Blue 199 and a thiazole-based compound are used. In this ink, about 1 mol % to about 20 mol % of the total counter ions in C. I. Direct Blue 199 are ammonium ions or organic ammonium ions.
An ink for ink-jet recording is provided in which a copper phthalocyanine dye is used and a thiazole-based compound is also used. In this ink, the mildew resistant properties are not impaired. Furthermore, the ink exhibits excellent ozone resistance, and the formation of a precipitate is prevented in the ink although the thiazole-based compound is used. In the ink for ink-jet recording containing the copper phthalocyanine dye and the thiazole-based compound, the used copper phthalocyanine dye has a specific structure, and about 1 mol % to about 20 mol % of the total counter ions of the dye are ammonium ions or organic ammonium ions.
An ink for ink-jet recording is provided in which copper phthalocyanine dyes and a thiazole-based compound are used. In this ink, the mildew resistant properties are not impaired, and the ink exhibits excellent ozone resistance. Furthermore, the formation of a precipitate is prevented in the ink although the thiazole-based compound is used. In the ink for ink-jet recording, as copper phthalocyanine dyes, two types of dyes are used together with a thiazole-based compound. Furthermore, about 1 mol % to about 20 mol % of the total counter ions in the two types of copper phthalocyanine dyes are ammonium ions or organic ammonium ions.
