Method for forming microporous fluorocarbon polymer sheet and product
US4196070A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 1977 |
| Grant date | Apr 1, 1980 |
| Priority date | — |
| Expiry date | Dec 12, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for forming a microporous sheet of fluorocarbon polymer (e.g., polytetrafluoroethylene). An aqueous dispersion of polytetrafluoroethylene which includes a dissolved water-soluble, crystallizable metallic organic salt, preferably sodium benzoate, is formed into a sheet. Water is evaporated from an exposed surface of the sheet to grow crystals of the organic salt dispersed throughout the sheet. Then, the sheet is sintered. After cooling, the salt crystals are leached from the sheet by dissolution in water to leave a porous structure suitable for such uses as a filtration membrane or as a separation barrier in batteries or electrolytic cells.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.