Preparation of Black Polyimide Films
Original Publication Date: 1983-Oct-01
Included in the Prior Art Database: 2005-Feb-07
Carbon and similar additives have been mixed with polyamic acid solution to provide polyimide films with light-barrier properties. Smooth, thin polyimide films are not possible since the particulates are usually too large. During cyclization (cure) an uneven distribution of the additive in the bulk chemistry occurs, with the additive concentrating at the substrate interface. Adhesion is usually poor since the molecular weight of the polyamic acid is sharply reduced with addition of the additive. Extremely thin films of black polyimide, having excellent adhesion and total opacity, have now been prepared. The polyimide has excellent thermal properties having withstood thermal exposure in air at 500ŒC for thirty minutes. Two formulations of polyamic acid solution, when fully cured, produce black polyimide films.