Super absorbent foams, and method for producing the same
CA 2189961 C · Owner: Gehrke, Stevin H. · Inventors: Gehrke, Stevin H.; Kabra, Bhagwati G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An absorbent, microporous foam comprising a crosslinked polymer having interconnected fluid cells distributed throughout its mass wherein the fluid cells have a diameter of between about 0.1 and about 100 µm and wherein the foam can rapidly absorb at least about twice its dry weight in fluid, is disclosed. A method for producing a microporous absorbent foam is also disclosed. This method comprises the steps of: (a) mixing a cross-linkable polymer and a first solvent to form a stable solution wherein the stable solution can be induced to phase separate; (b) inducing the stable solution to phase separate into a polymer-concentrated phase and a polymer-dilute phase after a predetermined period …
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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
- Filed May 12, 1995 and granted September 5, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 12, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 12, 2017.
- 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.