| 摘要 |
PROBLEM TO BE SOLVED: To provide an ink composition for an oil-based ballpoint pen, keeping lubricating property even under high writing pressure (writing load of 500 g), having excellent writing touch, reducing the wear of a ball seat, and providing good handwriting.SOLUTION: An ink composition for an oil-based ballpoint pen contains at least a coloring agent, an organic solvent and a thiadiazole compound, and the thiadiazole compound contains at least one kind of a thiadiazole compound selected from 2-amino-5-mercapto-1,3,4-thiadiazole, 5-methyl-1,3,4-thiadiazole-2-thiol, and 2-amino-5-methyl-1,3,4-thiadiazole. |
