| 摘要 |
PROBLEM TO BE SOLVED: To solve the problems encountered in products using transparent cases or exclusive holders for housing pencil leads for mechanical pencils, such as the problem of antistatic measures in the low-humidity winter environment wherein the humidity decreases to <=30% and of insufficient pressure-resistance of the leads at the zipper parts of the exclusive holders. SOLUTION: Composite fine particles are attached as core materials on the surface of the pencil lead body. Here, a water-repellent substance is arranged on the surface of a water-soluble polymer fine particle to allow a partial exposure of the surface of the water-soluble polymer fine particle. |
