Method of removing low molecular weight substance from polyimide precursor or polyimide containing low molecular weight substance
US6451965B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 2001 |
| Grant date | Sep 17, 2002 |
| Priority date | — |
| Expiry date | Nov 13, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/54
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of efficiently removing a low molecular weight substance from a polyimide precursor or polyimide in which the low molecular weight substance is dispersed as micro-domains, without using a large amount of an organic solvent. The method of removing a low molecular weight substance comprises subjecting either a polymer composition having a micro-domain structure made up of a continuous phase comprising a polyimide precursor and, dispersed therein, a discontinuous phase comprising a low molecular weight substance or a polyimide composition obtained from the polymer composition by converting the polyimide precursor into a polyimide to extraction with a combination of supercritical carbon dioxide and a co-solvent to thereby remove the low molecular weight substance. The co-solvent is preferably an aprotic polar solvent, more preferably a nitrogen compound solvent or a sulfur compound solvent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.