| 摘要 |
PROBLEM TO BE SOLVED: To enhance image preservability and coloring sensitivity by containing an isocyanate compound, an achromatic or hypochromic electron donative dye precursor and a thiol compound In a heat-coloring agent used for a thermal recording material. SOLUTION: An isocyante compound, an achromatic or hypochromic electron donative dye precursor and a thiol compound are contained in a heat-coloring agent used for thermal recording material. The isocyanate compound used herein is an isocyanate adduct compound having a melting point of 40 deg.C or higher, and as this isocyanate adduct compound, there is used a substance each preferably shown in formulas I, II. In the formulas, (m) expresses on integral number of 0-5 and (n) shows an integral number of 1-2. Then, a hydrogen atom of a benzene ring can be substituted by an aromatic compound residual moiety or an allphatic compound residual moiety or a heterocyclic compound residual moiety. Also, X1 , X2 show -SO2 -, -O-, -(S)q -, -(CH2 )q -, or the like. |
