INK COMPOSITION FOR A WATER-BASED BALLPOINT PEN, AND WATER-BASED BALLPOINT PEN

摘要

In order to provide an ink composition for an aqueous ink ball point pen with which a sufficiently high line intensity is obtained even when a thermochromic microcapsule pigment having a small average particle diameter is used and which is excellent in storage stability and a writing performance and an aqueous ink ball point pen, a composition of the above ink composition for an aqueous ink ball point pen is provided with such a constitution that it contains at least a microcapsule pigment which has an average particle diameter of 0.1 to 1.0 µm and in which a wall film is formed by an amino resin and a chemical substance which is a polymer comprising ketone as a main chain and has an acidic functional group in the chemical structure and which has an acid value of 3 to 40 (mgKOH/g).