THERMOCHROMIC BALLPOINT PEN

摘要

PROBLEM TO BE SOLVED: To prevent discontinuity of handwriting and decrease of a handwriting consistency from being generated by improving the fluidity of a thermochromic ink in a ballpoint pen tip.

SOLUTION: The thermochromic ballpoint pen includes a ballpoint pen tip 2 holding rotatably a ball 21 at the front end, and an ink housing part 3 provided with the ballpoint pen tip 2 at the front end and opened at the rear end. The thermochromic ink 7 and a following body 8 are housed in the ink housing part 3. The ballpoint pen tip 2 is constituted by a right circular cylindrical metal pipe. The amount capable of transferring the ball 21 in the axial direction is 10 μm-60 μm. The amount capable of transferring the ball 21 in the radial direction is 10 μm-60 μm. The ratio (B/A) of an inner diameter B behind a ball acceptance seat 23 of the ballpoint pen tip 2 to an outer diameter A of the ball is 1.01-1.15. The length L from the ball acceptance seat 23 of the ballpoint pen tip 2 to the rear end of the ballpoint pen tip 2 is 1 mm-3 mm.

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