| 摘要 |
PURPOSE:To maintain the viscosity of an ink layer upon melting at a high value, restrain permeation or transfer of the ink layer to an image receiving material and enable a gradually varied gradation to be obtained according to the quantity of heat applied to a thermal head by incorporating a high melt viscosity heat-fusible substance into an ink layer on a base. CONSTITUTION:A heat-fusible substance having a melting point of 42-60 deg.C and a melt viscosity of 1000-10000cP (100 deg.C), particularly a synthetic wax comprising a copolymer of two or more alkyl acrylates, is used for a heat-fusible ink layer on a base. When a material obtained by adding a pigment or dyestuff to the synthetic wax to color the wax and further adding required additives or the like to the colored wax is used for the ink layer, images with gradually varied gradations can be obtained. However, it is preferable to blend the synthetic wax with a heat-fusible substance having a higher melting point (60 deg.C or above) and a lower melt viscosity (not more than 1000cP (100 deg.C)) or thermoplastic resins. |
