OIL-BASED INK COMPOSITION FOR BALLPOINT PEN USING OIL-BASED INK

摘要

An oil-based ink composition for a ballpoint pen which comprises a colorant, a resin and a solvent selected from among an alcohol having a vapor pressure at 25°C of 0.001 mmHg or higher, a polyhydric alcohol and a glycol ether as a main solvent accounting for 50 % or more of the total solvent, and satisfies at least one of the following (a) to (C): (a) further comprises a neutralized product of a phosphate ester and polypropylene glycol; (b) further comprises a chemical substance represented by the following formula (1) or (2): (1) wherein R represents an alkyl group having 10 to 30 carbon atoms, or (2) wherein R represents an alkyl group having 10 to 30 carbon atoms; and (c) comprises, as the above main solvent accounting for 50 % or more of the total solvent, a solvent selected from among an alcohol having no aromatic ring in the molecular structure thereof, a polyhydric alcohol and a glycol ether, and further comprises a neutralized mixed product of a phosphate ester and an additional solvent selected from among an alcohol having an aromatic ring, a polyhydric alcohol and a glycol ether in an amount of 0.1 to 15 wt % relative to the total amount of the ink composition; and a ballpoint pen using the oil-based ink composition. The ink composition allows the suppression of the blur in the beginning of writing and can provide a feeling of writing excellent in softness and smoothness.