MORPHOGENETIC STUDY OF PARTICLE DOMAINS IN THERMOREVERSIBLE RECORDINGMEDIA COMPOSED OF POLYMERIC FILMS WITH DISPERSED FATTY-ACIDS

We have studied the morphogenetic conditions of particle domains in th ermoreversible recording media composed of polymeric films with disper sed fatty acids. These recording media have two different optical stat es, transparent or light scattering, depending on the thermal history. These states can be selected repeatedly by controlling the heating te mperature and can be recycled repeatedly. The essential requirement fo r this reversible behavior is the formation of small particle domains of the fatty acids, because a supercooling of the fatty acids occurs o nly when the small particle domains have been formed and plays a key r ole in the thermoreversibility. Morphological structures in the polyme ric films formed using various polymers and behenic acid were observed by a transmission electron microscope. On the other hand, the surface tension of the polymers and the fatty acids was measured by the conta ct angle method. By studying the relationship between the morphologica l structures and the surface tension, it was revealed that proper immi scibility between the polymers and the fatty acids is required for for ming the small particle domains of the fatty acids in the polymeric fi lm. We also report on the influence of the solvent on forming the part icle domains.