Process of making a cellulose acetate semipermeable membrane
US5645778A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1995 |
| Grant date | Jul 8, 1997 |
| Priority date | — |
| Expiry date | Jun 1, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2325/36
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Methods are disclosed for making semipermeable membranes from cellulose acetate and for making medical devices therefrom. In the process, a molten liquid comprising cellulose acetate (CA), a solvent for CA, and a non-solvent for CA is extruded to produce a membrane. The solvent and non-solvent are removed from the membrane to produce a semipermeable membrane having a water permeability. The semipermeable membrane is impregnated with a liquid consisting essentially of water to render the semipermeable membrane capable of being stored until time of use without undergoing a substantial loss in water permeability. The semipermeable membrane can be incorporated in a casing in order to produce a medical product, wherein the membrane is impregnated in the product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.