| 摘要 |
PURPOSE:To stabilize printing density at the time of repeated printing by providing a base film having a heat-resistant coating layer formed to the rear thereof, the foaming layer containing a foaming agent uniformly applied on the film and the ink layer arranged or the foaming layer. CONSTITUTION:An exudation type thermal transfer ribbon consists of a heat- resistant coating layer 11, a base film 12, an adhesive layer 13, a foaming layer 18, an ink layer 14 and a porous film layer 15. The foaming layer 18 expands at the time of printing to fill the part corresponding to the thickness of the part of the transferred ink layer 14 to keep the surface of the porous film layer 15 constant and, even when printing is carried out many times, it is prevented that the surface of the ink layer or that of the porous film layer becomes uneven. By forming the foaming layer from a composition allowing the thermal characteristics of the foamed part to be approximate to those of the part of the ink layer 14, even when printing is carried out many times, the thermal characteristics of the whole of the ink layer 14 are kept constant. Further, ink is extruded by the quantity corresponding to the expansion of the foaming layer 18 to control the exuding quantity of the ink constant. |
