WATER INK BALL POINT PEN

摘要

PURPOSE:To obtain a ball point pen particularly having excellent sagging preventing performance of ink by directly filling specific water-based ink in an ink duct mounted with a ball point pen tip in which a clearance between a ball and a ball retainer falls within a specific range. CONSTITUTION:Water-based ink contains aqueous medium, pigment and carboxyl group-containing crosslinking hydrophilic polymer containing carboxyl group- containing monomer swelled to become a particle diameter 0.5-10.0mum and dispersed in a gel state and at least two polymerizable unsaturated groups of 0.5mol% or more of an entire quantity of copolymerizable monoethylene monomer used together as desired and crosslinked with the crosslinking monomer. A water-based ink ball point pen is manufactured by directly filling the ink in an ink duct mounted with a ball point pen tip in which a clearance between a ball and a ball retainer falls within a range of 10.0-40.0mum.