Ink for ball-point pen and ball-point pen

摘要

In a ballpoint pen which is formed to have an ink-consumption value per unit area of 0.64 to 1.6 mg/cm<2>, the surface tension of the ink for the ball point pen is adjusted to a range of 16 to 32 mN/m so that blotting, line splitting and the like hardly occur, that the ink transferred onto the paper surface is ready to be dried and that fluctuation in the density and width of the written lines are less likely to occur due to a storage environment and to a writing condition.