| 摘要 |
PROBLEM TO BE SOLVED: To solve problems of the inability of writing due to the abrasion of the inside of a pen point in spite of the presence of residual ink in a ball point pen, of defective writing due to the abrasion of metal and pigment especially observed in a neutral ball point pen or when an ink which is apt to cause clogging, and of the detachment of the ball due to abrasion without requiring a special ink, a complex mechanism, or an expensive material and to obtain inexpensive, high-performance ball point pen by providing a multipurpose pen point material. SOLUTION: In the inside, between the diameter A of a circle circumscribed with channels 4 which lead ink to a pen point and its depth L, there exists a relationship given by 0.2XA<L<A. Moreover, By making the angle of the taper surface of the inside 3 60-90 deg., dispersion in the production of chips is eliminated. Moreover, a large effect is obtained by the combination with a backflow preventive mechanism. |
