PLASTIC SHEET AND CARD, AND METHOD FOR PREVENTING FORGERY OF CARD

摘要

PROBLEM TO BE SOLVED: To provide a method for composing a plastic sheet causing a reversible color change and having decorative and also forgery-preventing effects, and to provide the plastic sheet and a card in both of which a pigment assuming hues reversibly differing in different light sources is used. SOLUTION: This plastic sheet 1 features comprising a lanthanoid rare earth compound in a plastic resin.