| 摘要 |
Pigment dispersion stability of water-based inkjet inks in which water content is decreased by adding a low-polarity water-soluble solvent is to be improved in a simple way in order to provide an inkjet ink with excellent on-machine stability. A water-based inkjet ink is provided, which comprises at least water, a low-polarity water-soluble organic solvent, a pigment and optionally a basic substance, wherein the water constitutes 60 percent by mass or less of the total quantity of the ink while the water-soluble organic solvent constitutes 15 percent by mass or more of the total quantity of the ink, the pigment comprising a self-dispersible pigment that has anionic functional groups on its surface and contains, as counter ions, quaternary ammonium ions represented by the formula (1) described below. The basic substance is contained in an amount sufficient to allow the ink to have a pH value of 9 to 11:
wherein R 1 , R 2 , R 3 and R 4 independently represent a substituted or unsubstituted alkyl group. |
