| 摘要 |
PURPOSE:To provide a laminated film capable of being made thin while keeping mechanical strength, excellent in curling habit recovery after developing treatment and reduced in coating trouble by constituting the laminated film of at least two polyester layers and specifying a winding habit curling degree after heat treatment the recovery curl degree after hot water bath treatment and breaking strength in the longitudinal direction of the film. CONSTITUTION:A curl is applied to a film in the lateral direction thereof in order to make a curling habit hard to generate. In the case of two-layered constitution, two layers of the film consists of two polyester layers and the film is formed, for example, by a method wherein polyesters of the same kind or a different kind are extruded from separate extruders in a molten state and the molten polyesters are bonded in a laminar flow state in a conduit to be cooled and solidified to obtain a non-stretched film which is, in turn, biaxially stretched to be thermally fixed. By this method, a laminated film characterized in that a curling habit curl degree after that treatment is 135m<-1> or less and a recovery curl degree after hot water bath treatment is 45m<-1> or less and the breaking strength in a longitudinal direction is 16kg/mm<2> or more and excellent in curling habit recovery after developing treatment and reduced in coating trouble is obtained. |
