Lightweight expanded polytetrafluoroethylene membranes having high instrinsic strength and optical transparency
US12083482B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 2020 |
| Grant date | Sep 10, 2024 |
| Priority date | — |
| Expiry date | Jul 27, 2041 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2995/0077
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Thin, self-supporting biaxially expanded polytetrafluoroethylene (ePTFE) membranes that have a high crystallinity index, high intrinsic strength, low areal density (i.e., lightweight), and high optical transparency are provided. In particular, the ePTFE membrane may have a crystallinity index of at least about 94% and a matrix tensile strength at least about 600 MPa in both longitudinal nd transverse directions. In addition, the ePTFE membrane is transparent or invisible to the naked eye through a complete conversion of the PTFE primary particles into fibrils. The ePTFE membrane may have a thickness per layer of less than 100 nm and a porosity reater than 50%. Further, the ePTFE membrane is stackable, which, in turn, may be used to control permeability, pore size, and/or bulk mechanical properties. The ePTFE membrane may be used to form composites, laminates, fibers, tapes, sheets, tubes, or three-dimensional objects. Additionally, the ePTFE membrane may be used in filtration applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.