| 摘要 |
PROBLEM TO BE SOLVED: To provide a so-called pressurizing-type ball-point pen refill with such advantages that an ink hardly leaks, the ball also hardly comes off a ball house, the ink hardly blurs and further, the initial writing performance is excellent with the writing distance being sufficiently long. SOLUTION: The ball-point pen refill 10 is equipped with a tip 20, an ink storage pipe 30 and a tail plug 40, the ink 80 being packed at the tip 20 side of the ink storage pipe 30 and a pressurizing gas 90 being packed at the opposite side to the tip 20 of the ink storage pipe 30. The tip 30 is equipped with the ball 50 and a holder 60 and the ball 50 is formed so that its surface roughness Ra is 0.010-0.080 μm. The holder 60 has the ball house 61 and an ink guide hole 62 and the ball house 61 has a side part 70 and a base part 71. When the diameter of the ball 50 is given as ϕA and the inside diameter of the side part 70 as ϕB, the ball 50 is formed so as to satisfy 1.01<=ϕB/ϕA<=1.11. |
