| 摘要 |
PURPOSE:To obtain a thermal recording material having excellent raw preservability, high thermal response characteristics and high thermal color forming properties and less susceptible to lowering of the density of recorded images due to long-time preservation after thermal recording, by incorporating a sulfonic acid ester into a recording layer. CONSTITUTION:A sulfonic acid ester is incorporated in a thermal recording layer, in a thermal recording material having the thermal recording layer, which comprises microcapsules coating a diazo compound, a coupling agent or a basic compound therein, provided on a base. Preferable examples of the sulfonic acid ester include ethyl p-toluenesulfonate and butyl p-toluene sulfonate. The sulfonic acid ester is preferably incorporated as a core substance in the microcapsules, and more preferably, incorporated in the microcapsules together with the diazo compound. It is preferable to further incorporate one aromatic ether or ester and at least one of alcohols, phenols, sulfonamides and acid amides into a color forming layer, for improvement of raw preservability, improvement of thermal color forming properties and suppression of lowering in the optical density of recorded images due to long-time preservation after thermal recording. |
