OIL-BASED PIGMENT INK COMPOSITION AND OIL-BASED PIGMENT INK WRITING INSTRUMENT

摘要

PROBLEM TO BE SOLVED: To provide an oil-based ink composition containing titanium dioxide and a mica pigment in which the handwriting is sufficiently concealable and visible and ink can be stably discharged from a tip of a writing instrument without forming a hard cake.SOLUTION: There is provided an oil-based pigment ink composition which contains a titanium dioxide pigment, a mica pigment, a dispersant, an oil soluble resin and an organic solvent and has a viscosity at a shear rate of 76 (1/s) of 50 mPa.s, where the mica pigment has a 90% cumulative particle diameter of 20 μm or less. There is provided a marking pen in which the fiber diameter of a fiber constituting chips is 3 to 30 deniers.