METHOD FOR INTERCHANGEABLY EXPRESSING COLOR MEMORY TYPE PHOTOINDUCED COLOR CHANGE FUNCTION IN PICTURE BOOK AND INTERCHANGEABLE COLOR MEMORY TYPE PHOTOINDUCED COLOR CHANGING PICTURE BOOK

摘要

PROBLEM TO BE SOLVED: To provide a method of interchangeably storing/holding the memory of the colored state and discolored state of an optical color changing picture book, and an interchangeable color memory type photoinduced color changing picture book using the method.;SOLUTION: The picture book has an optical color changing image comprising a photochromic compound with the optical memory function (color memory type photoinduced discoloration function). The image is colored by irradiation of ultraviolet rays or solar light including ultraviolet rays, and the colored state is maintained. Then, the image is discolored by irradiation of visible light and the colored state is shifted to the discolored state. The picture book also has a color changing means including an ultraviolet absorbing agent and/or a light shading pigment for shading at least ultraviolet rays, so that the ultraviolet rays in solar light are blocked and the photochromic compound is discolored with irradiation of visible light. Then the state of the image is shifted to the discolored state and maintained in the discolored state. The color changing means is disposed in contact with or not in contact with the photoinduced discoloration image, so that the function of interchangeably storing/holding the memory of the colored state and the discolored state is provided.;COPYRIGHT: (C)2004,JPO&NCIPI