| 摘要 |
PROBLEM TO BE SOLVED: To provide an aqueous ink composition for ballpoint pen, which exhibits excellent writing performance stably for long term without causing viscosity change of ink, even in such a case that an aqueous ink using, as a shear viscosity reduction imparting agent, a polyglycerol isostearic acid ester with which high lubricity is obtained is stored in a high temperature atmosphere for a long period of time, and to provide a ballpoint pen housing the same.SOLUTION: The aqueous ink composition for ballpoint pen contains a pigment, water, a polyglycerol isostearic acid ester, and one or more selected from hydrogenated lysolecithin and lecithin hydroxide. A ballpoint pen housing the aqueous ink composition for ballpoint pen is also provided. In the aqueous ink composition for ballpoint pen, the blending ratio of the polyglycerol isostearic acid ester and one or more selected from hydrogenated lysolecithin and lecithin hydroxide is within the range of from 1:0.01 to 1:0.5. |
