| 摘要 |
PROBLEM TO BE SOLVED: To provide a writing instrument without cap for assuring a sealing state of a tip in a barrel with a simple constitution. SOLUTION: The writing instrument 1 without cap comprises a writing element 5 disposed in the barrel 2 to fill an ink for the writing instrument, a nib 6 of the writing element constituted to freely project from or retract in a tip opening of the barrel 2, and an inner cap 20 provided at the tip opening of the barrel 2 and formed of a rubber material or an elastic resin material. The cap 20 is formed with a slit in which the nib 6 is freely projected or retracted at the nib output side along an axial direction of the barrel. The instrument further comprises a blocking part for blocking the tip opening. The cap 20 is made of a material having a low gas permeability to an ink solvent contained in the ink and a material having a compression residual distortion factor specified according to JIS K 6262-1997 of 20% or less. |
