Ink composition for ballpoint pen based on water; refill for a ballpoint pen; ballpoint pen and ballpoint pen, disposable

摘要

A water-based ink composition for a ballpoint pen wherein the initial start of writing and writing over time is good, and no blur in handwriting occur and a stable writing performance can be sustained and good handwriting can be continuously formed. A water-based ink composition for a ballpoint pen dissolving or dispersing a coloring agent in an aqueous medium. The aqueous medium substantially contains no water-soluble organic solvent and is composed of water. The water-based ink composition includes a thickening inhibitor together with a shear thinning viscosity-imparting agent. As the thickening inhibitor, one or two or more are selected from a group of polyalkylene glycol, polypropylene glycol derivatives, polyvinyl alcohol, polyvinyl pyrrolidone, cellulose-based polymer compounds, polymer compounds having a polyalkylene oxide group and/or surfactants having a polyoxyethylene group.