Process for producing porous polyimide and porous polyimide
US6372808B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2001 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Oct 30, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/54
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A porous polyimide having a finely cellular structure and having a low dielectric constant and heat resistance. The porous polyimide can be produced by a process comprising adding a dispersible compound to a polyimide precursor to form a micro-domain structure in which the dispersible compound is dispersed in the polymer so as to have a size smaller than 10 &mgr;m and then removing the dispersible compound by extraction with supercritical carbon dioxide to thereby make the precursor porous, wherein the interaction parameter &khgr;AB between the polyimide precursor A and the dispersible compound B is larger than 3. This porous polyimide has an average cell diameter smaller than 5 &mgr;m and a dielectric constant of 3 or lower.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.