| 摘要 |
PURPOSE:To enhance color forming sensitivity, by containing a color forming substance having an average particle size of a specific value or less, a coupler and a water-soluble polymer. CONSTITUTION:Thermal recording paper markedly enhanced in color forming sensitivity is prepared using an aqueous dispersion containing a color forming substance having an average particle size of 1 mum or less and/or a coupler allowing said color forming substance to form a color at the time of heating and a water soluble polymer. This aqueous dispersion containing ultrafine particles can be easily prepared by distilling off an org. solvent from a dispersion consisting of an org. solvent solution of the color forming substance and/or the coupler and an aqueous solution of the water-soluble polymer. As the color forming substance, for example, a leuco form of a triphenylmethane type dye such as 3, 3-bis (P-dimetylaminophenyl)-phthalide or 3-(N-isoamyl-N-ethyl) amino-6-methyl-7-anilinofluorane is designated and, as the coupler, for example, phenol, gallic acid or the like are designated. As the representative example of the water-soluble polymer, there is polyvinyl alcohol or a derivative thereof. |
