| abstract |
A heat sensitive recording material having a recording layer formed on a substrate and containing a colorless or light-colored basic dye and a color acceptor, the heat sensitive recording material being characterized in that at least one ethyleneimine derivative of the following formula (1) is contained in the recording layer as a preservability improving agent for record images <IMAGE> (1) wherein R1 is direct bond, -O-, -S-, -SO2- or C1 DIFFERENCE C6 alkylene, R2 and R3 are each C1 DIFFERENCE C4 alkyl, C1 DIFFERENCE C4 alkoxyl or halogen atom, m and n are each zero or an integer of 1 to 4. |