| 摘要 |
PROBLEM TO BE SOLVED: To provide a water-based ink composition for a projecting/retracting ballpoint pen and a projecting/retracting ballpoint pen containing the same, having excellent dry-up resistance, starting writing well in the initial time or after lapse of the time without causing a trouble such as lack of ink and a drip of ink in handwriting and maintaining stable writing performance to continuously obtain excellent handwriting. SOLUTION: An ink composition housed in the projecting/retracting ballpoint pen wherein a handwriting tip part of a ballpoint pen refill projects/retracts from/into a front end opening of a shaft cylinder with operation of a projecting/retracting mechanism contains a dye, water, a water-soluble solvent and a copolymer salt of N-vinyl pyrrolidone and di-methyl aminoethyl methacrylate. The projecting/detracting ballpoint pen houses the water-based ink composition for projecting/retracting ballpoint pen. COPYRIGHT: (C)2009,JPO&INPIT |
