PHOTOGRAPHIC BASE PAPER HAVING GOLDEN PRINTING ON ITS BACK SURFACE

摘要

PROBLEM TO BE SOLVED: To obtain a photographic base paper having bright and glossy golden printing on its back surface which is produced by ordinary gravure system by using ink obtained by including interference pigment and special water soluble binder in printing ink. SOLUTION: The effect of the interference pigment (bright golden pigment and bright metallic pigment) is based on the selective reflection of a light beam. Especially, the proper interference pigment is mica pigment (deformed mica particles) and the core part of mica particle having plate-like shape has one or more metallic oxide layers. This generates an interference effect in visible light. TiO2 and/or Fe2 O3 is especially desired in order to coat the mica particle. A desired coloring effect is attained according to the type and the thickness of coating material. The interference pigment is used by combining ordinary translucent chromatic pigment in the printing ink. The water soluble binder or water dispersion binder, for instance, polyvinyl alcohol or polyvinyl pyrrolidone is especially sutiable for the binder.