AROMATIC POLYAMIDE FILMS FOR SOLVENT RESISTANT FLEXIBLE SUBSTRATES

• Main Authors: HARRIS FRANK W, JING JIAOKAI, SUN LIMIN, ZHANG DONG
• Format: Patent
• Language: English; Korean
• Published: 16.04.2014
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; BASIC ELECTRIC ELEMENTS; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERAL PROCESSES OF COMPOUNDING; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; SEMICONDUCTOR DEVICES; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

Films with optical transmittance of >80% between 400 and 750 nm and with coefficient of thermal expansion less than 20 ppm/° C. are prepared from aromatic polyamides that are soluble in polar organic solvents yet have glass transition temperatures>300° C. The films are cross-linked in the solid state by heating at elevated temperatures for short periods of time in the presence of multifunctional epoxides. Surprisingly, the optical and thermal properties of the films do not change significantly during the curing process. The temperature required for the crosslinking process to take place can be reduced by the presence of a few free, pendant carboxyl groups along the polyamide backbones. The films are useful as flexible substrates for electronic displays and photovoltaic devices.