A method of making optically clear oriented polyimide film.

摘要

In a method of producing a polyimide film, a concentrated solution 10 of a polyimide resin in a polar aprotic organic solvent is cast onto a film-supporting, cooled surface 20. The resultant film is contacted with an aqueous medium to coagulate the film, whereafter the coagulated film is stripped from the surface 20 and passed through a water bath 30 substantially to replace the solvent in the film with water. The water-containing film is then biaxially oriented and subsequently dried to remove water.