| 摘要 |
PROBLEM TO BE SOLVED: To provide an aqueous ink composition for a retractable ball point pen that has smooth writing touch, excels in resistance to ink drying-up at a ball surface, has good writing at beginning and after aging, and has no problems such as ink-skipping on handwriting and ink-dripping, and to provide a refill for the retractable ball point pen holding the ink composition, and the retractable ball point pen. SOLUTION: This aqueous ink composition for the retractable ball point pen is held in the ball point pen which permits a writing point of the ball point pen refill to retract in a top opening of a barrel by operation of a retractable mechanism. The ink composition includes at least a dye, water,λ-carageenan, xanthan gum, and an acrylic resin, wherein a numerical value (x), calculated from formula (1): loadings ofλ-carageenan (mass%)÷loadings of xanthan gum (mass%), is≥1.5, and viscosity of the ink is≤20 mPa s. The refill for the retractable ball point pen holding the ink composition, and the retractable ball point pen are also disclosed. COPYRIGHT: (C)2010,JPO&INPIT |
