OPTICAL RECORDING MEDIUM

摘要

PURPOSE:To improve the stability and reliability by using a composite body consisting of a compound having a photochromic functional group and a cross- linked polymer having a network structure in which the size of the meshes is nearly equal to or several times the size of the photochromic functional group. CONSTITUTION:The space where photochromic functional groups present in the meshes of a cross-linked polymer can freely move in an ordinary state is limited by restricting the size of the meshes or forming a proper side chain having a smaller size than the meshes. A reversible change between a light energy state and a low energy state is controlled by a steric hindrance effect. When writing or erasure is carried out with said composite body, it is necessary to cause a photochromic reversible change by heating the composite body to a temp. above the softening point. The chain of the cross-linked polymer is softened by the heating, so the steric hindrance effect is eliminated. The low energy state can be changed into the high energy state by irradiating light having the required specified wavelengths while supplying heat energy.