Polyamide-imide film and preparation method thereof

The embodiment of the invention relates to a preparation method of a polyamideimide film and the polyamideimide film prepared by the preparation method. The method comprises the following steps: in polymerization equipment, simultaneously or sequentially mixing a diamine compound, a dianhydride compound and a dicarbonyl compound in an organic solvent and reacting to prepare a polymer solution; transferring the polymer solution into a tank; purging the tank with an inert gas; casting the polymer solution in the tank onto a belt, then drying it to produce a gel sheet; heat-treating the gel sheet while the gel sheet moves to prepare a cured film; cooling the cured film when the cured film moves; and winding the cooled cured film by using a winding machine. The method can be used for preparing the polyamide-imide film with excellent optical performance and mechanical performance. 本申请实施方案涉及聚酰胺酰亚胺薄膜的制备方法和由此制得的聚酰胺酰亚胺薄膜。该方法包括：在聚合设备中，在有机溶剂中同时或依次混合二胺化合物、二酐化合物和二羰基化合物并反应，以制备聚合物溶液；将所述聚合物溶液转移到罐中；用惰性气体吹扫所述罐；将在所述罐中的所述聚合物溶液浇铸