| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball-point pen refill preventing the generation of an air bubble in ink caused by a centrifugal process, a temperature change and a change with the elapse time and generating no problem due to the generation of an air bubble even after the elapse of a long period of time. SOLUTION: The tip of a ball-point pen is provided to the leading end of a joint and an ink housing pipe is provided to the rear thereof, and the back surface of the leading end ball, which is held to the leading end part of the tip in a freely rotatable manner, is pressed by the leading end of the coil spring inserted in the tip to bring the leading end ball into close contact with the inner edge of the ball holding part of the tip. The ink housing pipe is filled with aqueous ink having the so-called shear- thining propertiers, which are fundamentally low in viscosity, have a statically high viscosity and lowers in viscosity by the rotation of the leading end ball at the time of writing to allow ink to flow out, and a follower comprising a grease-like translucent non-drying substance to follow the consumption of ink is provided to the rear end of the ink. In the ball-point pen refill thus constituted, the rear end part of the tip is caulked at a required place not only to prevent the slip-off of the rear end of the coil spring but also to form an air flow channel between the outer peripheral part of the coil spring and the inner hole of the tip. |
