Patent ID: 9718977
Date: 2017-08-01
CPC Classifications: C09D,G01N

Claim:
1. A water-based ink for ink-jet recording comprising: a pigment; a surfactant; and water, wherein a slope value of the water-based ink at an evaporation rate of 0% is not more than 15%/hour; a slope value of the water-based ink at an evaporation rate of 30% is not less than 9%/hour, the slope value of the water-based ink being measured by a centrifugal transmission sedimentation method; the surfactant is a nonionic surfactant and a content of the surfactant in the water-based ink is in a range of 0.2% by weight to 0.5% by weight; and the pigment is a carbon black of which an average particle size is in a range of 140 nm to 160 nm and a content of the carbon black in the water-based ink is in a range of 8% by weight to 10% by weight.