| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ballpoint pen which presents smooth feeling of writing without causing ink clogging even if aqueous ink including a glass flake pigment is used. <P>SOLUTION: The seat 45 of the ball housing room 40 of a ballpoint pen tip 5 is converged into a center hole 46 and communicates with an ink leading hole 12. The seat 45 is provided with a groove 47 which extends crosswise radially. The width W of the groove 47 is 0.15 to 0.5 mm, and is preferably 0.20 to 0.35 mm. In the equatorial section of a writing ball 10, there is space 48 of 20 to 40 μm between the writing ball 10 and the ball housing room 40. The opening of the ball housing room 40 is caulked, and in a section which lies within the ball housing room 40 being a section on the side of exposure from the equator of the writing ball 10, space 48 of 20 to 40 μm is secured in any section. <P>COPYRIGHT: (C)2012,JPO&INPIT |
