USE OF POLYMIDES PREPARED FROM POLYAMIDE ACIDS

• Main Author: HUPFER, BERND
• Format: Patent
• Language: English; German
• Published: 28.11.1990
• Subjects: ADHESIVES; BASIC ELECTRIC ELEMENTS; CABLES; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; COMPOSITIONS BASED THEREON; CONDUCTORS; CORRECTING FLUIDS; DYES; ELECTRICITY; FILLING PASTES; INKS; INSULATORS; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; POLISHES; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING ORDIELECTRIC PROPERTIES; THEIR PREPARATION OR CHEMICAL WORKING-UP; USE OF MATERIALS THEREFOR; WOODSTAINS

Described are polyamic acids, at least 50 mole-% of which are comprised of recurrent units corresponding to the general formula I: (I) wherein, R1 is a mono-, di-, tri- or tetranuclear aromatic group and X is O, S, CO, SO2 or CR2R3, each one of R2 and R3 being H or CH3. A polyamic acid of the present invention, in the form of a solution, is applied to a substrate, for example, a semiconductor device, to form a protective layer thereon, and is converted into polyimide by heating. As against comparable compounds known in the art, the polyamic acids of the present invention are distinguished by a lower inherent viscosity at an unchanged molecular weight and, consequently, by an improved processability at an equally good thermal stability.