Preparation of cellulose acetate membrane and its use for polar solvent-oil separation
CA 1263003 C · Owner: Wernick, David L. · Inventors: Wernick, David L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Cellulose acetate membranes, demonstrating good resistance to ketone and possessing the ability to separate ketone dewaxing solvent from dewaxed oil are described. They are prepared by using a carefully selected nonaqueous solvent process. The cellulose acetate membrane is cast gelled and, annealed in an entirely organic solvent system preferably, selected according to solubility parameter considerations. After casting but before gelling, the more volatile of the two solvents is partially evaporated. The solvents used are such that no solvent exchange process is necessary to prepare the cellulose acetate membrane for use in ketone/oil separation procedures. Alternatively, the solvents are …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted November 21, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 21, 2006.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.