| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an oil-based ink for a ball point pen with little initial writing blur even after standing for a long period of time in a state where the nib is exposed to air under an environment accompanied with temperature change and with little leakage of ink from a pen point while leaving it face down.SOLUTION: There is provided an oil-based ink for a ball point pen containing at least a coloring material, 1,2-alkane diol having 8 to 12 carbon atoms, alkyl phosphate ester having a polyoxyethylene chain, and water of 0.1 to 10 wt.% based on the total amount of the ink and an organic solvent having an ether group or a hydroxyl group of 50 wt.% or more based on the total solvent.</p> |
