| 摘要 |
PROBLEM TO BE SOLVED: To provide an ink composition for a water-based ballpoint pen which is excellent in air-intake property, ink-dripping property and writing feeling, and giving good handwriting. SOLUTION: The ink composition for a water-based ballpoint pen comprises water, a colorant, a shear viscosity reduction-imparting agent, polyvinylpyrrolidone and a phosphate surfactant, characterized in that xanthan gum and a crosslinked acrylic polymer are used together as the shear viscosity reduction-imparting agent, and at 20°C, the ink viscosity at 384.0 sec<SP>-1</SP>shear rate is 15-100 mPa s and the ink viscosity at 1.92 sec<SP>-1</SP>is 300-2,000 mPa s. COPYRIGHT: (C)2008,JPO&INPIT |
