| 摘要 |
PURPOSE:To prevent the lowering of color forming sensitivity in such a case that a lubricant is added and to enhance whiteness, light fastness, humidity resistance and plasticizer resistance by using a compound represented by a specific formula and solid at room temp. and having a specific solubility parameter as a sensitizer. CONSTITUTION:A sensitizer for a thermal recording material is composed of a compound represented by general formula R1-Y-CO-R2 (wherein R1 and R2 are a phenyl group, a naphthyl group, a tetrahydronaphthyl group or a group selected from these groups substituted with a 10 or less C hydrocarbon group and Y is 1-4C alkylene group or a 2-4C alkenylene group) and solid at room temp. and has a solubility parameter of 9.5-12. The thermal recording material containing this sensitizer is markedly enhanced in color forming sensitivity and generates no lowering of color forming sensitivity even when a specific metal salt of higher fatty acid (lubricant) is added and is also excellent in whiteness (background fog) and generates no lowering of whiteness even when the lubricant is added. An image part provides high-grade capacities such as light fastness, humidity resistance, plasticizer resistance or the like. |
