Aromatic polyamide films for solvent resistant flexible substrates
US9856376B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 2012 |
| Grant date | Jan 2, 2018 |
| Priority date | — |
| Expiry date | Apr 28, 2035 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/269
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
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 crosslinked 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.