| 摘要 |
PROBLEM TO BE SOLVED: To provide a ballpoint pen refill in which writing tip body is hardly worn and ink consumption is stabilized until the completion of ink.SOLUTION: A ballpoint pen tip 1 is composed of a stainless steel material, and includes, in a tip body 2, a ball holding chamber 3, an ink circulating hole 7 formed at a bottom wall center of the ball holding chamber, and a plurality of ink circulating grooves 6 radially extending from the ink circulating hole; and holds the ball while a part of the ball is projected from a tip end edge 2a by caulking the tip end 2a inside. A ballpoint pen refill is configured such that: mounting the ballpoint pen tip 1 on the leading end of an ink housing cylinder, and oily ink for the ballpoint pen with specified ink viscosity and containing carbon black and salt-forming dye of sulfonic acid and basic dye in the ink housing cylinder as a colorant, and when ink consumption A mg at a time point of 0-100 m and ink consumption B mg at 100 m before the completion of ink satisfy 0.8≤A/B≤1.2. |
