| abstract |
PURPOSE: To obtain the title film in which a metal oxide is uniformly dispersed in a state of fine particles and which is excellent in mechanical strengths and dimensional stability, by casting or applying a composition formed by adding a metal oxide sol to a varnish of, e.g., an aromatic polyimide on or to a base and heating it. n CONSTITUTION: A composition is obtained by adding 1W100pts.wt. (in terms of the metal oxide) metal oxide sol such as silica sol, alumina sol, iron oxide sol or titania sol and, optionally, 5wt.% or below silane coupling agent (e.g., methyltrimethoxysilane) to 100pts.wt. (in terms of component (a)) aromatic polyimide (a) having repeating units of formula I (wherein Ar 1 is a group of any one of formulas IIWIV, Ar 2 is a group of any one of formulas VWVII, R is a 1W3C alkyl, alkoxy or a halogen, X is O, S, SO 2 , a 1W13C alkylene or a group of formula VIII and m and n are each 0W2) or a varnish (b) of a polyamic acid as a precursor of component (a). This composition is cast on or applied to a base such as glass and either dried at 60W170°C for 30W120min or heated at 200W400°C. n COPYRIGHT: (C)1988,JPO&Japio |