| 摘要 |
PURPOSE:To provide a heat-sensitive recording material having a high color density and excellent in contrast, by a method wherein a color forming layer is provided by using dispersions of a leuco dye and of an acidic substance which are prepared by using a specified copolymer as a dispersing agent. CONSTITUTION:A copolymer of acrylamide and hydroxypropyl acrylate having a molecular weight of about 50,000-300,000 is used as a dispersing agent. Namely, a dispersion obtained by pulverizing and mixing 1pt.wt. leuco dye[e.g., 3,3- bis(p-dimethylaminophenyl)phthalide]and about 0.01-2pts.wt. said dispersing agent in water, a dispersion obtained by pulverizing and mixing 1pt.wt. acidic substance[e.g., 2,2-bis(p-hydroxyphenyl)propane]and about 0.01-0.2pts.wt. said dispersing agent in water, and a binder (e.g., polyvinyl alcohol) are mixed with each other. A heat-sensitive color-forming layer forming liquid thus obtained is coated on a support and is dried to obtain a heat-sensitive recording material. |
