MANUFACTURE OF THERMAL RECORDING MATERIAL

摘要

PURPOSE:To stably prepare a thermal recording material of high quality having sufficient whiteness by using a coating solution for a thermal color forming layer enhanced in sensitivity consisting of a dye precursor dispersion and a developer dispersion both of which are finely pulverized. CONSTITUTION:A coating solution for thermal recording is prepared by mixing a dye precursor dispersion containing a substantially colorless electron donating color forming dye precursor and a developer dispersion containing an electron acceptive developing compound developing a color upon the contact reaction with said dye precursor at the time of heating. In this preparation process, at the time of the preparation of at least one of both dispersions, the mean particle size of the dispersion is set to 0.7mum or less and an undercoat layer having a surface with pH of 4.5-7.5 is formed between a sheet like substrate and the color forming layer. This coating solution is applied to at least one surface of the sheet like substrate to be solidified to make it possible to prepare a thermal recording material without lowering whiteness.