| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a writing utensil equipped with a friction material which discolors an image or a handwriting, formed freely, by using a reversible heat discoloring ink. <P>SOLUTION: This writing utensil 2 internally stores at least, a reversible heat discoloring ink 6. The reversible heat discoloring ink 6 is composed of a microcapsule pigment with an average particle diameter ranging from 0.5 to 5.0 μm dispersed in an aqueous solvent. The microcapsule pigment also includes a high temperature side discoloration point within the range of 25 to 65°C. The writing utensil 2 is equipped with a friction material 1 composed of an elastic solid, and the friction material 1 includes a fretting part 11 of a projecting curved surface shape with a curvature radius R of 1 to 10 mm. The image or handwriting of the reversible heat discoloring ink 6 formed on a paper with permeability, is heated above the predetermined temperature level by the frictional heat generated by manual fretting operation. Thus, the change of color takes place from the first color developing state to the second color developing state, from the color developing state to the color erased state or from the color erased state to the color developing state. <P>COPYRIGHT: (C)2011,JPO&INPIT |
