To provide an ink for inkjet, decreasing granular impression of images, improving gradation expression of images, obtaining images of high image quality, and capable of simultaneously increasing recording rate.
The ink for inkjet contains at least two colorants of a colorant (a) and a colorant (b), wherein the ink comprises at least one solvent selected from the group consisting of solvents represented by the formula HO-(CH2CH2O)m-H (m≥3) and the group consisting of solid solvents solid at 25°C and 50% relative humidity, and wherein the colorant (a) and the colorant (b) satisfy relations classified into (1) to (3). (1) The content of the colorant (a)≥that of the colorant (b). (2) When a CIELAB color space dieplay system of an image obtained by an ink singly containing the colorant (a) is luminance La* and that by an ink singly containing the colorant (b) is Lb*, La*≥Lb*. (3) When a color difference between the initial color of the image obtain by the ink singly containing the colorant (a) and the color after preserving at a high temperature and a high humidity under shielding light is ΔEa and a color difference in the same meaning but by the colorant (b) is ΔEb, ΔEa≥ΔEb.
TOMIOKA HIROSHI
YAMAGAMI HIDEKI
TOCHIHARA SHINICHI
OSUMI KOICHI
TSUJI ITARU
KAWABE MINAKO
Toshieko Kondo