| 摘要 |
PROBLEM TO BE SOLVED: To provide an ink backflow prevention body composition having high practicability excellent in ink backflow prevention performance and aging stability, which satisfies shock resistance performance and ink follow-up performance without requiring consideration of size of an ink storage cylinder and has shape retention performance in long-time duration.SOLUTION: An ink backflow prevention body composition for a writing instrument which is arranged on a rear end surface of ink directly stored within an ink storage cylinder of the writing instrument and advances in accordance with consumption of the ink is made by adding a gelation agent and a crystalline poly-α-olefin while setting polybutene as base material. A ball point pen refill in which the ink backflow prevention body composition for the writing instrument is arranged on a position brought into contact with the ink rear end surface within the ink storage cylinder is also provided.SELECTED DRAWING: None |
