| 摘要 |
PROBLEM TO BE SOLVED: To provide an aqueous ink composition for writing instruments, excellent in stability without pH decrease with time in the case of using a basic dye-based coloring material in the aqueous ink composition for writing instruments as a coloring material.SOLUTION: An aqueous ink composition for writing instruments contains at least one kind of diethylenetriamine pentaacetic acid and salts thereof, amines and a basic dye-based coloring material, and a contained amount of the diethylenetriamine pentaacetic acid and slats thereof is 0.004 to 2 mass% based on the total amount of the ink composition. |
