| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method where a light-discolored image including a photochromic compound in a colored state is immediately decolored or discolored with frictional heat without troublesomeness of waiting its decoloration with the lapse of time.SOLUTION: The photochromic compound is decolored or discolored with frictional heat obtained by performing friction, e.g., to an image obtained by coloring a heat reversible photochromic compound selected from a spirooxazine derivative or a spiropyran derivative using a friction body by a light irradiator.</p> |
