| 摘要 |
PROBLEM TO BE SOLVED: To provide an ink-backflow preventive material which controls the separation of liquid, is excellent in ink-backflow preventive performance, impact resistance, and ink flexibility and chemically stable, does not cause a remarkable decrease in ink viscosity even when shear force is applied, and keeps viscosity constant when packed in a writing implement or preserved in bulk and the writing implement filled with the material. SOLUTION: In the writing implement in which ink is packed directly in an ink housing cylinder, an ink-backflow preventive material composition in which a hardly-volatile organic liquid (B) gelatinized or solidified by a gelatinizing agent is dispersed in a hardly-volatile organic liquid (A) or the organic liquid (A) with its viscosity increased by a thickner is used. |
