AROMATIC POLYAMIDE FILM AND ITS MANUFACTURE

PROBLEM TO BE SOLVED: To shorten the time of releasing a film off a substrate, manufacture the film at a high speed, improve the corrosion and winding properties of a substrate and improve the productivity at a low cost by laminating another layer of another specified value of a metal ion content at least on one face of a layer of a specified value of a metal ion content. SOLUTION: A film is a laminated film formed of two layers or more, and constituted of a layer A containing 2-1,000 ppm meal ions, on one face of which a layer B of less than 2 ppm metal ion content is laminated. When the metal ion content of the layer A is less than 2 ppm, the film is easily charged to form a defective winding shape, while when the content therein is beyond 1,000 ppm, the film is short of flexibility and the elongation is smaller and easily to be cut to cause the lowering of yield. When the metal ion content is less than 2 ppm, the release properties of the film off a substrate is good in the manufacture of the film to shorten the drying time and improve the film manufacturing rate, while when the content is 2 ppm or more, the release properties become worse. Thus the good release properties and winding properties of the film for the substrate are provided to carry out the high speed film manufacture, the corrosion of the substrate is hard to be generated, productivity is superior and the cost is low.