| 摘要 |
There is disclosed the polyester film for laeder tapes which can provide commercially highly valuable laeder tapes which are very fine and uniform in the surface roughness of the etched portion and excellent in appearance, and do not adversely affect magnetic tapes. There is also disclosed the process for preparing a polyester film for laeder tapes which can exhibit the following excellent effects. This process allows the production of a leader tape with a desired thickness pattern at a high reproducibility. Furthermore, this process allows the production of commercially highly valuable leader tapes which are very fine and uniform in the surface roughness of the etched portion and excellent in appearance. Moreover, since many leader tapes can be processed at a time, leader tapes with a desired thickness pattern can be produced at a low cost. This invention are related to the polyester film for leader tapes , comprising a polyester film having been brought into contact with an alkaline liquid, to be etched at least on one side, to have a thickness pattern and a process for producing a polyester film for leader tapes, comprising the step of bringing a polyester film into contact with an alkaline liquid, to etch the polyester film at least on one side, with the etched depth controlled differently from position to position, for processing to have a desired thickness pattern. It is preferable that etching is effected by immersion into an alkaline liquid. <IMAGE> |
