| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat-sensitive recording sheet with little ground fog even when it is exposed for a long time under a high temperature condition by controlling OD values on color developing concentration when a heating block at 100 deg.C is brought into press contact with the sheet under a pressure of 800 g/cm<2> for 5 seconds and color developing concentration when a heating block 150 deg.C is brought into press contact with the sheet under a pressure of 800 g/cm<2> for 5 seconds. SOLUTION: The heat-sensitive recording sheet having a heat-sensitive recording layer provided on a substrate is characterized by a constitution in which, the color developing concentration when the heating block at 100 deg.C is brought into press contact with the heat-sensitive recording sheet under a pressure of 800 g/cm<2> for 5 seconds is made to be at most 0.20 by the OD value (optically reflective density) and the color developing concentration when the heating block at 150 deg.C is brought into press contact with the heat-sensitive recording sheet under a pressure of 800 g/cm<2> for 5 seconds is made to be at least 1.20 by the OD value. |
