Friction body, writing instrument and writing instrument set

摘要

A friction body that produces frictional heat allowing development, disappearance or change of color of handwriting formed with a writing instrument for producing thermochromic handwriting, with the friction body having a friction coefficient of 0.2 to 1.0 when rubbed against paper surface, and a writing instrument for use in forming thermochromic handwriting which is equipped with the friction body and a writing instrument set including the frictionbody and a writing instrument for use in forming thermochromic handwriting.