| 摘要 |
PURPOSE:To enhance reproducibility of density variations and intermediate gradation, by gradually lowering the contents of a heat conduction controlling agent and a coloring agent in each ink layer, in a multilayer thermal transfer sheet having a laminate construction of a plurality of heat-fusible ink layers formed respectively of heat-fusible inks which differ in melting point and each of which comprises a coloring agent. CONSTITUTION:Each of thermal transfer layers 2, 3, 4 is formed of a composition comprising a thermoplastic resin, a wax, a coloring agent 5 and a heat conduction controlling agent 6. the melting point of the thermoplastic resin or wax constituting each layer is gradually lowered, in the direction away from a base 7, in decrements of about 5-25 deg.C. The content of the heat conduction controlling agent 6 in each layer is gradually lowered, in the direction away from the base 7, in decrements of not less than about 0.5wt%. Further, the content of the coloring agent 5 in each layer is gradually lowered, in the direction away from the base 7, in decrements of about 3-7wt%. With this arrangement, the heat applied from the base 7 side is faithfully transmitted to the thermal transfer layer, resulting in that intermediate gradations are favorably expressed. |
