| abstract |
In a retroreflective sheet having a surface layer 1 composed of at least one layer and a plurality of retroreflective elements 3, 4, 5 located below it, the retroreflective elements 3, 4, 5 are provided. The incident light is retroreflected in the direction of the light source, and at least one layer of the surface layer 1 disperse | distributes and added the optical coherent color material by which the hue changed with time, and the surface of the core material covered with one or more coating layers which are substantially transparent. It is an optical coherence layer, and reflects incident light in the reverse direction to the light source, and at least one layer of the retroreflective sheet is a colored layer containing a coloring material for coloring the retroreflected light, and the retroreflected light and the specularly reflected light Expresses different colors. As a result, two or more different colors are expressed under the interference of light under daylight color, and the color of the retro-reflected light is different from the color under the daylight color due to night-time light emission, and a color different from that of the retro-reflected light on the opposite side to the incident light. It provides a color variable retroreflective sheet. |