| 摘要 |
PURPOSE:To ensure clear printing in use of a thermal transfer sheet and prevent ununiform take-up of a ribbon from occurring due to plastic deformation or thermal deformation of the ribbon, by optimizing the planar orientation factor and the axial orientation ratio of a biaxially oriented polyester film. CONSTITUTION:One side of a biaxially oriented polyester film having a planar orientation factor of 0.04-0.09, an axial orientation ratio of 1.05-1.40 and a thickness of 1-12mum is coated with a thermosetting resin, and a coloring material layer is provided on the other side by coating. The value of the planar orientation factor is a parameter indicating the degree of orientation of polymer molecules in the plane of the film, and a lower value indicates a higher planar orientation. If the coefficient is less than 0.04, wrinkling of a ribbon after thermal transfer is severe, so that an error in pitch is generated, causing ununiform take-up. If the factor is greater than 0.09, enhancement of thermal conductivity is insufficient. If the axial orientation ratio of the film is less than 1.05, the film is elongated, resulting in ununiform take-up. On the other hand, if the ratio is greater than 1.40, tearing will easily occur at the time of ribbon fabrication or at the time of thermal transfer. The thermosetting resin is not particularly limited. |
