Water based ink composition for rollerball pen

摘要

Disclosed is a water based ink composition for a rollerball pen that includes at a least colorant, a water-soluble organic solvent, water, a shear thinning viscosity property-providing agent, a lubricant, and a bubble suppressant. The ink composition includes a phosphate-ester based surfactant having a structure of general formula 1 as the lubricant, and an erythorbic acid or a derivative thereof as the bubble suppressant (n represents an integer of 1 or more, R represents an alkyl group having carbon numbers of 12 to 15, and R' represents H or R-(C₂H₄O)_n-).