| 摘要 |
PURPOSE:To perform a recording medium of a multilayer structure in which colored parts are recorded without superposing on first and second photochromatic materials to increase its recording density twice or more in density by specifying the first and second materials, and irradiating beams having different optical energies. CONSTITUTION:First and second photochromatic materials are laminated, the first material is made of spiropyrane compound represented by a formula I (where R1, R2, R3 include at least one of hydrogen atom, hydroxyl group, halogen group, nitro group, amino group, alkyl group, alkoxy group, and aryl group), the second material is made of fulgide compound represented by a formula 11 (where R4, R5 include at least one of hydrogen atom, hydroxyl group, halogen group, nitro group, amino group, alkyl group, alkoxy group, and aryl group, an optical energy required to color the second material is large, and the colored parts of the first and second materials are not superposed each other. |
