Heat-resistant polymer foam, process for producing the same, and foam substrate
US6503427B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 2000 |
| Grant date | Jan 7, 2003 |
| Priority date | — |
| Expiry date | Jun 6, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31681
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A heat-resistant polymer foam is disclosed which has excellent heat resistance, a fine cellular structure, and a low apparent density. The heat-resistant polymer foam comprises a heat-resistant polymer having a glass transition point of 120° C. or higher, e.g., a polyimide or polyether imide, and has an average cell diameter of from 0.01 &mgr;m to less than 10 &mgr;m. This heat-resistant polymer foam can be produced by, for example, impregnating a heat-resistant polymer under pressure with an non-reactive gas such as carbon dioxide, which is in, e.g., a supercritical state, reducing the pressure, and then heating the polymer at a temperature exceeding 120° C. to foam the polymer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.