Aromatic polyamide films for transparent flexible substrates
US9457496B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2011 |
| Grant date | Oct 4, 2016 |
| Priority date | — |
| Expiry date | Dec 22, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention is directed toward transparent films prepared from soluble aromatic copolyamides with glass transition temperatures greater than 300 C. The copolyamides, which contain pendant carboxylic groups are solution cast into films using N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), or other polar solvents. The films are thermally cured at temperatures near the copolymer glass transition temperature. After curing, the polymer films display transmittances >80% from 400 to 750 nm, have coefficients of thermal expansion of less than 20 ppm, and are solvent resistant. The films are useful as flexible substrates for microelectronic devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.