Heat-expandable solid pattern forming sheet

Abstract

A heat-expandable solid image forming sheet includes a base sheet, a heat-expandable layer formed of a material containing foaming particles on the base sheet and capable of expanding when heated, and a protective layer formed by a coating process on the heat-expandable layer. The base sheet has a strength higher than that of the protective layer in order to suppress the rise of a solid pattern toward the base sheet. The base sheet may be a PET film having a tensile strength of 0.5 kg/cm.sup.2 or above expressed by stress induced therein at 1% elongation at 100.degree. C. An image is formed using a light-absorptive material on the protective layer that absorbs light energy and converts the absorbed light energy into heat. When the heat-expandable solid pattern forming sheet carrying the image is irradiated with light, portions of the heat-expandable layer corresponding to the image are heated by the heat generated from the light-absorptive material. These heated portions expand and rise toward the protective layer to form a solid pattern corresponding to the image.

Dependencies are inferred from the claim text.