| 摘要 |
PURPOSE:To prevent the deterioration in density of a coloring image, by a method wherein a thermal recording sheet is formed by laminating an overcoat layer composed of propylene glycol alginate etc., on a thermal color-forming layer formed on a substrate. CONSTITUTION:A coating liquid prepared of a color-forming substance, a color- developing substance, and an additional substance such as a binder and a filler, if necessary, is applied on a substrate, such as a paper, film, and synthetic paper, and dried; in this manner, a thermal color-forming layer is formed. On the other hand, a coating liquid is prepared as a water solution or water emulsion of propylene glycol alginate, or that of the propylene glycol alginate, a water-soluble polymer, or/and a difficultly water soluble polymeric compound. This coating liquid is applied on the aforesaid thermal color-forming layer and dried; in this manner an overcoat layer is laminated, and then a thermal recording sheet is produced. In this thermal recording sheet, the deterioration in density of a coloring image due to a plasticizer can be improved to a great extent. |
