| 摘要 |
PURPOSE:To improve repetitive stability by providing an optically recordable part by using a mixture or reaction product of a spiro compd. and the zinc salt of arom. hydroxycarboxylic acid in which a hydroxyl group and carboxyl group exist in the adjacent positions as a photochromic material. CONSTITUTION:The optically recordable part is provided by using the mixture or reaction product of the spiro compd, and the zinc salt of the arom. hydroxycarboxylic acid in which the hydroxyl group and carboxyl group exist in the adjacent positions as the photochromic material. The spiro compd. to be used is not particularly limited and, for example, a spirobenzopyrane compd. and spironaphthoxazine compd. are more preferable examples. The utilization permit and prepaid card which are wide in a color developing range and are excellent in heat resistance, light resistance, image stability, and repetitive stability are obtd. in this way. |
