| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a writing utensil which includes a heat discoloring writing ink which generates color change in a line by being rubbed with a rubbing body and makes the degree of the rubbing required for the discoloration visually recognizable. <P>SOLUTION: The writing utensil stores, as a writing ink, an ink which includes heat discoloration property by which the color is changed from a low temperature color condition to a high temperature color condition as the temperature rises, and the color is changed from the high temperature color condition to the low temperature color condition as the temperature goes down, and includes a rubbing body which generates heat discoloration by the temperature rise due to the friction caused by rubbing the writing ink of the line. The rubbing body is also provided with the heat discoloration property by which the color is changed from the low temperature color condition to the high temperature color condition as the temperature rises, and the color is changed from the high temperature condition to the low temperature condition as the temperature goes down. <P>COPYRIGHT: (C)2011,JPO&INPIT |
