Patent ID: 9209333
Filing Date: 2015-12-08
Classification: C08J,H01L,Y02E,Y02P,Y10T

Abstract:
1. A process for producing a polyimide film, comprising: providing a solution of a polyimide precursor prepared from an aromatic tetracarboxylic acid component comprising 3,3′,4,4′-biphenyltetracarboxylic dianhydride in an amount of 95 mol % or more and an aromatic diamine component comprising p-phenylenediamine in an amount of 95 mol % or more; flow-casting the polyimide precursor solution on a support, followed by heating, thereby preparing a self-supporting film of a polyimide precursor solution; imidizing the self-supporting film by heating the self-supporting film while fixing at least both edges of the self-supporting film in the width direction to complete imidization, thereby preparing a polyimide film; and heating the polyimide film at a temperature of 500° C. or higher in a substantially unstressed state while not fixing one edge or both edges of the polyimide film in the width direction, thereby preparing a polyimide film which has a dimensional change from 25° C. to 500° C. within a range from 0% to +0.6% based on the initial dimension at 25° C.