| abstract |
A reversible thermal recording medium comprises a composition containing a color former, a developer, a reversible material capable of reversibly changing the state of the composition by supplying heat energies with two different values, and, as required, a phase separation controller which permits changing the phase separation speed of the developer at temperatures in the vicinity of the melting point of the phase separation controller, at least 80% by weight of the reversible material being a sterol compound in which the carbon-to-carbon bond between 2- and 3-positions of the stroid skeleton is a single bond, the carbon-to-carbon bond between 3- and 4-positions of the steroid skeleton is a single bond, a hydroxyl group is attached to the carbon atom in at least the 3-position of the steroid skeleton, and a specified chemical structure is bonded at 16- and 17-positions of the stroid skeleton, and the phase separation controller being provided by a low molecular organic material, the maximum carbon chain length there of being at least 10. |