Ink for ball point pen

摘要

An ink for a ball point pen contains at least one or plural kinds of organic solvents, colorants and resins and further contains fine particle silica having a primary average particle diameter of 7 to 40 nm and a specific surface area (BET method) of 50 to 380 m2/g. The ink for a ball point pen is prevented from leaking out of the pen tip, is not damaged smooth writing feeling and does not cause clogging at the pen tip.