Method of manufacturing film for film capacitor and film for film capacitor

摘要

When extrusion of a molten resin by means of an extruder is started, a simple polyetherimide resin is melt extruded from a lip portion 7a of a T-die 7, and a film of the simple polyetherimide resin is molded. The molding material is then switched to a resin composition including the polyetherimide resin and a fluorine resin and then a film of the resin composition is continuously extruded and molded from the T-die 7. Having been covered with a very thin film 8a of the simple polyetherimide resin, on a flow passage face of the lip portion 7a of the T-die 7, a resin composition layer 8b including a polyetherimide resin and a fluorine resin, which has affinity with the film 8a, is then formed at a center part.

主权项

1. A method of manufacturing a film for a film capacitor, the method comprising:
injecting a molding material consisting of one or more polyetherimide resins into an extruder, and then melt extruding the film for the film capacitor from a lip portion of a tip end of a T-die; pinching and cooling the extruded film for the film capacitor between a pressure roll and a cooling roll in a pulling unit; and winding the cooled film for the film capacitor with a predetermined thickness by means of a winder, wherein: melt extruding the molding material consisting of one or more polyetherimide resins at a starting step of extrusion operation of the extruder is performed in an inert gas atmosphere obtained by replacing air in the extruder with an inert gas; and switching the molding material consisting of one of more polyetherimide resins to a resin composition obtained by adding 1.0 to 30.0 parts by mass of a fluorine resin to 100 parts by mass of a polyetherimide resin after the molding material consisting of one or more polyetherimide resins is fully extruded and molded, to thereby mold the film for the film capacitor.