| 摘要 |
PURPOSE:To impart high thermal sensitivity and excellent storage stability, by providing an under coat layer containing a specific sulfonamide compound between a support and a thermal color forming layer. CONSTITUTION:An under coat layer containing a sulfonamide compound represented by formula (wherein R1 and R2 are hydrogen, a halogen atom, an aryl group, a trihalomethyl group or an alkyl group) is provided between a support and a thermal color forming layer. The sulfonamide compound acts as a sensitizer and benzenesulfoanilide is designated. A leuco dye is adapted alone or in a combination of two or more ones but the leuco compound of a triphenylmethane or fluorane dye is used. The leuco dye is used in a range of 0.2-2pts.wt. of a coupler and the amount to be used of the sulfonamide compound used in the under coat layer is set to 0.2-1pt.wt. of the total amount of the leuco dye and the coupler. By this method, a thermal recording material having high thermal sensitivity and extremely excellent in storage stability is obtained. |
