| 摘要 |
PROBLEM TO BE SOLVED: To solve such an issue that a phenomenon of a decrease in an ink discharge amount with time or a thin spot in handwriting, when a writing utensil, using ink containing an organic solvent, which adopts a rubberlike elastic body as a sealing member for a nib of a ball point pen tip, is used. SOLUTION: The sealing member whose weight decrease rate is 10% or less when it is treated by soaking in ethanol is used. |
