Polytetrafluoroethylene porous film and preparation and use thereof
US5234739A · kind A · utility
81Cited by
7References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1992 |
| Grant date | Aug 10, 1993 |
| Priority date | — |
| Expiry date | Jul 22, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31544
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A polytetrafluoroethylene porous film, which is prepared by stretching a semisintered polytetrafluoroethylene material and heating the stretched material at a temperature higher than the melting point of sintered polytetrafluoroethylene, has an area ratio of fibrils to nodes of from 99:1 to 75:25, an average fibril diameter of from 0.05 to 0.2 .mu.m, a largest node area of not larger than 2 .mu.m.sup.2 and an average pore size of from 0.2 to 0.5 .mu.m and achieves low pressure loss.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.