| 摘要 |
PROBLEM TO BE SOLVED: To provide a refill ink cartridge which is made by filling an ink cartridge with pigment ink for refill without cleaning a used ink cartridge for pigment ink, and exhibits a good discharge stability.SOLUTION: (1) A refill ink cartridge is made by filling a used ink cartridge with pigment ink for refill, which has a pH higher than the pH of pigment ink remaining in the used ink cartridge. (2) In the refill ink cartridge described in (1), the pigment ink for refill is ink containing at least a pigment, wetting agent, surfactant, and pH adjuster. |
