Aromatic polyamide films for transparent flexible substrates
US12110372B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 2021 |
| Grant date | Oct 8, 2024 |
| Priority date | — |
| Expiry date | Aug 23, 2041 |
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.