| 摘要 |
PURPOSE:To provide a thermal recording material excellent in image reliability and generating almost no color development of a background due to an org. solvent, by using p-toluenesulfonylhydrazide and/or p,p'-oxybis(ben zenesulfonylhydrazide) as a coupler. CONSTITUTION:In a thermal recording material utilizing the color forming reaction between a leuco dye and a coupler, p-toluenesulfonylhydrazide and/or p,p'-oxybis(benzenesulfonylhydrazide) is used as a coupler. This coupler has no coupling capacity itself and shows the coupling capacity for the first time when is converted to an org. acid by thermal cracking and, therefore, a background part forms no color by an org. solvent such as alcohol. As a result, the reliability of an image part can be enhanced. This coupler is used generally in a range of 1-10pts., pref., in a range of 2-6pts.wt. of 1pt. of the leuco dye. The decomposition aid used together with the coupler has not only the function lowering the decomposition temp. of the coupler but also the function accelerating a decomposition speed. |
