| 摘要 |
PURPOSE:To obtain a base material having excellent heat resistance and tough properties by using a film manufactured by drawing and treating a styrene polymer mainly having syndiotactic structure as a base film. CONSTITUTION:A film manufactured by drawing and treating a styrene polymer mainly having syndiotactic structure is employed as a base film in the ink ribbon. The styrene polymer, weight average molecular weight of which must be brought to 10,000 or more, particularly 50,000 or more regarding molecular weight, is preferable as the styrene group polymer employed. The polymer having weight average molecular weight of 10,000 or less cannot be drawn sufficiently. The polymer must be drawn at draw ratios of twice or more in the direction of orientation on uniaxial orientation and of one and a half times or more in the direction of each orientation (the biaxial directions) on biaxial orientation in the draw ratios of drawing treatment. When the draw ratios are too small, the film is not proper as the base film regarding the physical properties of the film acquired. The ink ribbon displays extremely high heat resistance while it is excellent even in performance such as adhesive properties, travelling, etc. |
