Ink composition and image formation method

Abstract

The invention provides an ink composition containing at least: a water-soluble organic solvent; a pigment; water; and a nonionic polymer thickener. The content of the water-soluble organic solvent is from 5 weight % to 30 weight % relative to the total amount of the ink composition. The ratio of Vhigh/Vlow, in which Vhigh represents 25° C. viscosity (mPa·s) measured at a shear rate of 1.5×105 (s−1) and Vlow represents 25° C. viscosity (mPa·s) measured at a shear rate of 3.0×103 (s−1), is from 0.70 to 0.95. The invention further provides an image formation method including at least ejecting the ink composition onto an image recording medium using an image formation apparatus to form an image on the image recording medium.

Dependencies are inferred from the claim text.