Membrane separation of uncoverted carbon fiber precursors from flux solvent and/or anti-solvent
US4606903A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 27, 1984 |
| Grant date | Aug 19, 1986 |
| Priority date | — |
| Expiry date | Apr 27, 2004 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01F9/145
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Flux solvents and/or pitch neomesophase anti-solvents used in the generation of carbon fiber precursors from pitch are separated from mixtures of such solvent and uncoverted carbon fiber precursors by contacting said mixtures with asymmetric hydrophobic membranes under conditions of reverse osmosis. The membranes used in this separation are asymmetric polyimide membranes and asymmetric polyvinylidene fluoride membranes. Separation conditions include a contacting pressure sufficient to overcome the osmotic pressure of the solvent. The pressure is typically about 300 to 1000 psi. Contacting temperature is about 0.degree. to 100.degree. C., preferably about 20.degree. to 80.degree. C. The membrane of choice is an asymmetric polyimide membrane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.