Mechanism of Color Development for UV-Fixable Thermal Recording Material

Abstract

Our UV-fixable thermal recording material principally consists of diazonium salts contained in microcapsules, coupling agents, oganic bases and thermo-sensitizers.
It was found that color development characteristics of this recording material depends not only on the eutectic point of the composition as in general thermal recording material, but also on the temperature dependence of the phsical properties of the wall of the microcapsule and the interaction between the wall of the microcapsule and the composition. That is, the wall of the microcapsule works as a valve that opens at the glass transition temperature.
The thermo-sensitizer is the ingredient that not only reduces the eutectic point of the coupling agent and the organic base, but also reduces the glass transition temperature of the wall of the microcapsule.