| 摘要 |
PROBLEM TO BE SOLVED: To provide a water-based pigment ink for a ballpoint pen excellent in storage stability enough to cause no blur after long-term storage. SOLUTION: The water-based pigment ink for a ballpoint pen comprises a crosslinkable poly(N-vinyl carboxylic amide) and an aliphatic organic acid bearing two or three carboxylic groups. In one embodiment of the water-based pigment ink for a ballpoint pen, the aliphatic organic acid is citric acid, succinic acid, tartaric acid, malic acid or malonic acid. |
