Patent ID: 8889764

Claim:
A water-based ink for inkjet recording comprising a binder resin, a color material, a surfactant, and a water-based solvent, wherein: the surfactant is a fluorine-containing surfactant; the water-based solvent comprises: water, a water-soluble organic solvent (A) having a surface tension of 45 mN/m or less, and a water-soluble organic solvent (B) selected from the group consisting of cyclic solvents containing a nitrogen atom or a sulfur atom, cyclic ester solvents, lactic acid esters, β-alkoxypropionamide, alkylene glycol diether, alkylene glycol monoether monoester, and dimethyl sulfoxide, and an amount of the water-soluble organic solvent (B) is 20 to 40% by mass based on a total amount of the water-soluble organic solvent (A) and the water-soluble organic solvent (B); and the ink satisfies the condition that, where an ink weight change rate when the ink is heated is expressed by the following equation: ink weight change rate (%)=((weight of ink before heating−weight of ink after heating)/weight of ink before heating)×100 (1) a viscosity of the ink is more than 10 mPa·s and 30 mPa·s or less, the viscosity being measured by an E-type viscometer at 25° C. and 1 rpm over the ink weight change rate range of 0% to 10%, (2) a viscosity of the ink is 200 mPa·s at any one of the ink weight change rate within 35% or more and 55% or less, the viscosity being measured by the E-type viscometer at 25° C. and 1 rpm, and (3) a surface tension at 25° C. of the ink at the ink weight change rate of 5% is lower than a surface tension at 25° C. of the ink at the ink weight change rate of 0%.