Thermally stable, low birefringent copolyimide films
US11084906B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 2012 |
| Grant date | Aug 10, 2021 |
| Priority date | — |
| Expiry date | Feb 23, 2036 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31721
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A class of solvent resistant, flexible copolyimide substrates having high optical transparency (>80% from 400 to 750 nm) that is retained after brief exposure to 300° C., near-zero birefringence (<0.001) and a maximum CTE of approximately 60 ppm/° C. is disclosed. The copolyimides are prepared from alicyclic dianhydrides, aromatic cardo diamines, and aromatic diamines containing free carboxyl groups. The substrates are manufactured from solutions of the copolyimides containing multifunctional epoxides in the form of single layer films, multilayer laminates and glass fiber reinforced composite films. The substrates can be used in the construction of flexible optical displays, and other microelectronic and photovoltaic devices that require their unique combination of properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.