| 摘要 |
PURPOSE:To eliminate the occurrence of blank omission in printing and to increase the strength of paper by a method wherein a substrate is formed of a plastic film and an undercoat layer whose main constituent is a thermo-melting substance is provided between the substrate and a heat-sensitive color developing layer. CONSTITUTION:Roughened part of a heat-sensitive surface caused by sticking of dust on a plastic film, nonuniformity in coating or the like deteriorate the close contact with a thermal head in printing and cause blank omission. In order to prevent the occurrence of the phenomenon of this blank omission, an undercoat layer whose main constituent is a thermo-melting substance is provided as a cushion layer for the thermal head between a substrate and a heat-sensitive color developing layer. Thereby the close contact with the thermal head is improved and the problem of blank omission is solved. Although an arbitrary thermo-melting substance is applicable as the one to be used for the undercoat layer, a substance whose melting point is 70 deg.C or above is preferable in consideration of surface blushing in storage, and particularly a substance having a melting point of 80 to 180 deg.C is preferable. When the melting point is higher than these temperatures, the effect for prevention of blank omission decreases. |
