Fabrication of fluoropolymer hollow fibers for asymmetric membranes
US5209883A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 1991 |
| Grant date | May 11, 1993 |
| Priority date | — |
| Expiry date | Apr 17, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D69/08
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Asymmetric hollow fibers comprising a fluoropolymer, and a process for making such fibers. The hollow fibers are useful for making fluid separation membranes, especially gas separation membranes. In one embodiment of the process of this invention, a polymer dope having a viscosity of about 3000 poise or greater is prepared by solvating the polymer in a solvent system containing about 40%-90% N-methyl-2-pyrrolidone and about 60%-10% propionic acid by weight. The dope is dry-jet wet-spun into hollow fibers using a water-NMP core solvent. The fibers are coagulated in methanol. The fibers are then coated with a highly permeable material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.