| 摘要 |
PROBLEM TO BE SOLVED: To prevent reverse or forward flow of ink by arranging a follower filled with white pigment ink mixed so as not to impair fluidity and following to consumption of ink at a rear end of the ink. SOLUTION: The ballpoint pen comprises a tip 12 having an end ball 13 and pressed to be brought into close contact with an inner edge of a ball embracing part 12a at an end of the tip 12 at normal time and released from the close contact state at the time of writing, and a follower 18 having an ink containing tube 16 provided rear of the tip 12 and containing at least white pigment such as titanium oxide, polymer hollow fine particles or the like and gelatinizing agent and filling white pigment ink mixed to prevent sedimentation of the pigment without impairing fluidity and following to the ink in the case of consuming the ink at a rear end of the ink. In the case of the ink having a viscosity of 10000 cps (by an E type viscometer at 1 r.p.m. and 25 deg.C) or less, there exists a tendency of sedimentation of the pigment. In the case of the ink having 50000 cps or more, a problem arises at the time of discharging the ink. Hence, the viscosity of the ink is set to 10000 to 50000 cps. |
