Cellular polymer containing perforated cell windows and a process for the preparation thereof
US5250579A · kind A · utility
24Cited by
1References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1992 |
| Grant date | Oct 5, 1993 |
| Priority date | — |
| Expiry date | Sep 28, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S521/908
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for preparing a cellular polymer containing perforated cell windows in the presence of a perforating agent being a substance that has a critical surface free energy of less than about 23 mJ/m.sup.2 is disclosed. The cellular polymers obtained according to this invention have a fine cell structure and show enhanced dimensional and thermal insulation stability. The invention also relates to rigid polyurethane foam prepared in the presence of, for example, particulate poly(tetrafluoroethylene) or a liquid polyfluoro- or perfluorocarbon, with a boiling point of at least 130.degree. C., as perforating agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.