Water base ink for ink-jet recording and method for preparing water base ink for ink-jet recording

Abstract

A water base ink for ink-jet recording is provided, which is excellent in time-dependent stability of ink characteristics, which can be stably jetted over a long period of time, and which makes it possible to perform the high quality recording. The water base ink for ink-jet recording contains a self-dispersing type water-insoluble particulate coloring agent, a compound represented by the following formula (1), a surfactant having a nitrogen atom in a molecule, water, and a water-soluble organic solvent, wherein a surface tension is 30 to 50 mN/m, and a ratio of change of the surface tension after storage at 60° C. for 2 weeks is less than 5%: R1—O—(CH2CH2O)x—SO3Na  (1) wherein R1 represents an alkyl group and x is 20 to 30 in the formula (1).

Dependencies are inferred from the claim text.