Preswelling of regenerated cellulose membranes for organic separations and the use thereof
CA 1254007 A · Owner: Imperial Oil Limited · Inventors: Hafez, Mahmoud M.; Koenitzer, Bernard A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for preswelling and drying hydrophilic regenarated cellulose, membranes involving solvent exchange with a hydrogen bond breaking hygroscopic polar solvent followed by drying. The resulting membrane can be directly used, without further treatment for polar organic liquid permeation such as polar dewaxing solvents from dewaxed oil. Preferred hygroscopic polar solvents are sulpholane, dimethyl-sulphoxide (DMSO) dimethylformamide (DMF), n-methyl, pyrrolidone (NMP) other disubstituted sulphoxides, disubstituted sulphones other disubstituted formamides and dimethylamine (DMA) and morpholine. Most preferred solvent is DMSO. The method of the present invention is useful not only for …
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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 May 16, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 16, 2006.
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Timeline
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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.