| 摘要 |
PROBLEM TO BE SOLVED: To provide an ink composition which can give a ball-point pen made proof against poor ink delivery after interruption of writing, skipping and a feeling of unsmooth writing during continuous writing, and marked reduction in ink delivery during long-time use by adding a spherical silica powder to an ink. SOLUTION: There is provided a ball-point pen ink composition prepared by adding a spherical powder to an ink containing at least one organic solvent, a colorant, and a resin. It is desirable that this composition has a viscosity of 1,000-20,000 mPa s at 25 deg.C. The spherical silica powder has a mean particle diameter of about 0.1 to 5μm and is used in an amount of 0.01-5 wt.% based on the ink. It is particularly desirable that the spherical silica powder has been surface-treated with a silicone. The spherical silica powder is first dispersed in the organic solvent to be used in the ink and adding such an amount of the dispersion as to give a necessary concentration to an ink. The ink may additionally contain, if necessary, various additives, a surfactant, a higher unsaturated fatty acid, etc. |
