Patent ID: 8241414

Claim:
A water-based ink for ink-jet recording, comprising: a pigment; water; an anionic surfactant represented by the following general formula (1); and complex salt forming an anionic zirconium complex ion: R—O—(CH 2 CH 2 O) n —X − M + (1) where in the general formula (1), R represents a hydrophobic group, X − represents an anionic group, M + represents an alkali metal ion, an ammonium ion, or a quaternary ammonium ion, and n represents an integer of 1 to 30; wherein the anionic zirconium complex ion is [Zr(CO 3 ) 2 (OH) 2 ] 2− , and a counter ion in the complex salt is an alkali metal ion or a quaternary ammonium ion; wherein the amount of the anionic surfactant represented by the general formula (1) to be added relative to the total amount of the water-based ink in the range from about 0.05 wt % to about 0.15 wt %; and wherein the solid content of the complex salt relative to the total amount of the water-based ink is in the range from about 0.1 wt % to about 0.8 wt %.