INK FOR OIL-BASED BALLPOINT PEN

摘要

PROBLEM TO BE SOLVED: To provide an ink for an oil-based ballpoint pen which does not leak even under a high-humidity environment, and causes no blur of handwriting.SOLUTION: An ink for an oil-based ballpoint pen contains at least a coloring agent, an organic solvent, a polyvinyl butyral resin, and a cyclohexanone resin. A weight ratio of the cyclohexanone resin with respect to the polyvinyl butyral resin having a molecular weight of 66,000 or more is more than 7.0 times and less than 10.0 times.